Hello. If you are willing to travel to Bangalore. The one option you have is by air. And now a days all air lines are offering discounts. Kindly check the indigo website. They are new year celebrations discounts.
Happy travelling
Can you search in facebook a group called RE cruzados, its royal enfield rider enthusiats group. we have around 20-55 members who have done the entire run of Cochin to leh and even nepal along the return. they can help you with better intenary.