Hi Divyansh! A Bali trip for one person for a duration of 4days/3nights can cost anywhere between Rs. 25,000-45,000 (including food, accomodation and activities). It is hihgly dependent on the activities you engage in, where you stay etc.
Here are some holiday packages that will give you detailed travel plans for Bali and guide you through your trip. You can also get customised packages from Tripoto. All you need to do is fill the form next to the package, specifying your requirements.
Happy Travelling!