The subcontinent of India, is sometimes referred to as the Maratha Empire, however central authority from the Imperial capital of Delhi is loose and it is probably better to speak of the region as a collection of loosely federated autonomous kingdoms rather than a monolithic state.
To the west lies the Caliphate and Afghanistan. To the north; the Himalayan Mountain range with the states of Nepal, Sikkim, Bhutan and Tibet. To the east is Arakan and Toungoo. To the southeast is the island of Lanka with the sovereign nations of Kotte and Jaffna. To the southwest are the Laccadive and Maldive islands which are protectorates under Anglia (Anglian Indian Ocean Islands).
The closest the region has to a head of state would be the current Chhatrapati or Emperor, Shahaji III.
The nominal capital is Delhi.
India boasts a multitude of different cultures, religions and languages, none of which has 'official' status in the empire. Leading politicians are probably right to be cautious in promoting a religion or language over another, unsure of the forces which could be unleashed.
The national currency is the Indian Rupee (INR). All of the hundreds of kingdoms are permitted to mint their own designs.
Whilst archeological digs have dated civilisation on the Indus river to 2500 BC the later 'Vedic Period' which would incorporate the composing of the earliest Hindu scriptures coincided with the spread of agriculture and settled civilisation to the Ganges river.
Alexander the Great would reach the Indus river and Greek contempories wrote of the Nanda Empire on the Ganges and the 'Gangaridai' futher east on the Ganges Delta. The fearsome reputation of both of these entities would be factor in stopping Alexander's seemingly unstoppable conquest in 326 BC. Perhaps they were too hasty as the Nanda Empire was about to be usurped by the Maurya whose rule would extend to almost all of the subcontinent by 250 BC. The 3rd Mauryan Emperor, Ashoka the Great, would be repulsed by his own bloody conquests and the devastation caused and converted to Buddhism, spurring a peaceful and prosperous period but his successors would have less success and the empire slowly eroded.
Power would rest with various local dynasties until the rise of the Delhi Sultanate in 1206 which would conquer and dominate the subcontinent by 1330 after which it splintered and local sultanates once again consolidated their power. Islam would make considerable inroads into the subcontinent driven by the new rulers.
In 1526 the armies of Babur captured Delhi and the Mughal Empire was born. In time Mughal authority declined, thanks in part to in-fighting within the imperial family but also as conflicts with Caliphate Persia, Afghanistan and internal wars built up. In 1759 the Maratha Confederacy, which had steadily built up considerable power over the previous century, would comprehensively defeat Emperor Jahandar Shah II supplanting the Mughal dynasty in Delhi. Their victory was less than total however and following their defeat to Kanadhar in 1761 the Imperial court accepted some loosening of grip on the regions in return for fealty, which was more or less necessary to avoid more ruinous war.
Hence the Marathas Emperors control the old Marathas heartlands plus Delhi and its not inconsiderable hinterland, a few fortresses on border passes, but little more than that. The vast majority of the rest of the subcontinent is divided into smaller states which all pay fealty to Delhi but largely act as independent states. Most align themselves with the largest states in their culture/language, forming blocs.
An Imperial army operates, mostly drawn from Imperial territory and the smaller states, but increasingly this is symbolic and the armies of individual states are better equipped and trained. The dedicated Marathas army is much larger and well-regarded for instance than its Imperial counterpart even though they share some of the same structure and leadership. Likewise an Imperial navy concerns itself mainly with patrolling against piracy and smuggling whilst the larger states buy state-of-the-art battleships and submarines from European shipbuilders.
European and Leifian Relations
Throughout all of the internal struggles, the influence of various European and Leifian nations slowly increased. Initially solely interested in trade the Europeans would have operated from trading posts along the coasts, some merely warehouses on docks but slowly as trade increased to the benefit of the westerners and the native princes, these would be expanded to fortressed trading posts or full-blown miniature states in their own right (such as UKN's Indian Sovereign Territory (Ksheera Puri) or Portuguese Goa).
Since the first visits to Calicut by the Portuguese in 1445 the vast riches and fine goods of India have been readily snapped up by home markets. Considerable rivalry between the trading powers over the right to export spices, textiles and in time, tea, would spill out into war as the various foreign parties sowed intrigue between the various dynasties and states for their own gain. In return the local rulers have access to Western education and military assistance. More recently tourism has begun to grow; a visit to India largely supplanting the previously popular 'Grand Tour' of Europe in the itineraries of the upper classes.
Mostly the foreign trading concessions operate under treaty with the local powers but not all Indian rulers are happy about these trading arrangements. Madras for instance is vocal in its desire to take full control of its own trade and has clashed with Anglia in the Laccadive islands on more than one occasion.
As one might expect, the governmental systems of the Indian states vary wildly. Almost all are monarchies, mostly hereditary, and mostly governed as autocracies. Some states, driven by long relationships with European and Leifian countries are moving toward parliamentary democracy, though still with considerable oversight by the local ruler.
The very smallest states, some only a few square miles in area, tend to outsource their government to larger neighbours or to Delhi.
The Marathi emperors occasionally issue decrees, mostly related to foreign relations and as long as they don't intrude too far into the rights of states then are usually accepted without a fuss.
Since 1948 there has been a 'Congress' where delegates from every state can debate and draw attention to issues which affect the entire region. It normally sits in Delhi though smaller sessions have been held in other locations. However this is not a law-making body per se, more an advisory body which does seem to influence states' internal politics. It has also been instrumental in ensuring the smooth construction of a region-wide rail network, aligning policing and facilitating trade.