A1. India is Full of Tourism Places which you can Visit Throughout the year, But if we try to find places according to months, below are the Places:
Rajasthan - October to March
Jammu & Kashmir - April to June & November to January
Uttarakhand & Himachal You Can Travel Any Time in The Year
South India Travel - December to March
A2. India Travel best Time is From September to March Because of Cold Weather in Winter Time
A3. The best and cheapest travel time for India travel is between June 20 to Sep 30 in This period you can get the lowest price from hotels, travel agents, & car rental companies.
A4. Yes, You can travel in India as a solo traveler. But avoid Crowded Places if you are a foreigner.