Jai Singh I of Amber receiving Shivaji a day before concluding the Treaty of Purandar (12 June 1665)
The Maharaja of Benares and his suite, 1870s

Raja (ɑː/; also spelled Rajah, from Sanskrit राजन् rājan-), is a title for a monarch equivalent to king or princely ruler in the Indian subcontinent and Southeast Asia.

The title has a long history in the Indian subcontinent and Southeast Asia, being attested from the Rigveda, where a rājan- is a ruler, see for example the daśarājñá yuddhá, the "Battle of Ten Kings".

Raja-ruled Indian states

While most of the Hindu salute states were ruled by a Maharaja (or variation; some promoted from an earlier Raja- or equivalent style), even exclusively from 13 guns up, a number had Rajas :

Hereditary salutes of 11-guns 
Hereditary salutes of 9-guns (11-guns personal) 
Hereditary salute of 9-guns (11-guns local) 
Hereditary salutes of 9-guns 
Hereditary salute of 9-guns[1][2]
Personal salute of 9-guns