Bali, jeju island, Singapore, Mauritius for international. India you can go ladakh, chikmagalur, mangalore . if you want to explore temples go for madurai, rameshwaram
Best places in India for solo traveller :
1. Udaipur
2 Pondicherry
3 Mussoorie
4 Coorg
5 Goa Outside India
1. Bali
2. Singapore
3 Cambodia
4Vietnam
5 Dubai
6 even Europe is quite safe and doable
In India I would suggest Kashmir (because people are very nice and supportive - even I travelled that too solo)
Other would be Manali, gokarna, jodhpur, udaipur.
Also, ladakh.
I have personally trvaled to all these places, solo or with a female friend and can vouch for them in terms of safety and experience.
Rajasthan --Udaipur,Pushkar,Jaipur, Jodhpur,
Meghalaya
Uttrakhand-- Valley of flowers, Auli, Almore,Lansdowne,Corbett
Karnataka-- Hampi, Coorg, Mysore, Bangalore, Udupi
Ponducherry
Himachal
North East India is always a Go-go for everyone, especially ladies travelling alone. The places are really soothing and safe. One can find females on roads, in hotels and hone stays and even on tourist spots to help everyone.
Have a nice tour😊
Vietnam is brilliant.
North of Thailand for sure (it's like nothing you expect from Thailand)
Laos is beautiful
Indonesia...islands around and Bali
Also Bali if you can avoid Kuta and Chengu is mesmerising.