I found this gem of a book on Delhi Universitys DSPACE site.It gives a very good idea of warfare in ancient India.For a fuller understanding it is best if you read it in conjunction with Kautilya’s “Arthashastra”.( freely availaible as a downloadable pdf here: Arthashastra of Kautilya)
War in Ancient India
Veer Savarkar was one of those great sons of Mother India who could weild a sword and a pen with equal ease.His book “Hindu Pad Padshahi” gives an excellent overview of the pan Indian struggle of the Marathas to establish a Hindu empire where Hindus did not have to pay jizya,nor were their life and property under threat by fanatical Muslims and Christians.
Reading this book is a must for every right mineded Indian just to get an idea of the holy mission of the Maratha Empire.
Hindu Pad Padshahi-Veer Savarkar