I have been to Mysore n ooty it was safe for everyone.
Christmas I'm going solo to Kochin, Vagamon and Varakal. All this place is safe for everyone. Many city has zostel so stay at zostel it's very safe and full of entertainment
There is no such place as unsafe in India.
I have traveled to most parts of India all by myself and I'm good. even then I would suggest few places-
Rishikesh Shimla
Jaipur
Coorg
Meghalaya
Daman & Diu
Prayagraj
Agra
All these places are under budget and a must visit for Solo travellers
Vietnam..especially north Vietnam is great for solo travel. it's cheap, you have stunning views and great experiences. people in the north villages along with backpackers are some the kindest people you will ever meet. i spent 2 months there and for good reason