Rajgir is generally a safe destination for solo female travelers. The locals are usually friendly and helpful, and there are many holy sites that draw tourists, so you won't feel out of place. As always, it's important to stay vigilant, especially at night or in more secluded areas. Keep your belongings secure at all times and follow the cultural norms to respect local customs. Avoid isolated areas after dark, and always let someone know of your plans for the day.