How much money is needed for survival?
It is a tricky question because not enough info. Well, it is all relative I guess. Well, everyone has a unique perception of what a decent life means from type and quantity of food to size and comfortability of residence.
It's not about how much you earn, but how much you keep.
The most expensive thing about living costs is the rents. Once you have that accounted for most other things are pretty decent value.
So, here is a reference point for salary, if you can spend only HALF of your salary for rental, and save other HALF for transportation, groceries, recreation, apparel and utilities then it's likely you can live survive.
The best way to make it worth is whether your lifestyle can match the same way as your own lifestyle in your home country based from your spending not a stranger spending patterns.
You can use the World Cost of Living Spreadsheet (crowd sourced data) to calculate items such as accommodation, transportation, groceries, recreation, apparel and utilities according to your needs.
Reference/download : World Cost of Living Spreadsheet (crowd sourced data)
Look, it almost depends upon the way you are living your life. If you think you can live your life in less money or if you are extravagant it's your choice. Suppose if your are living single then, you need Rs 5000 - Rs 7000 for PG (including food), Rs. 500 - Rs. 1000 for Mobile, Rs 1500 - Rs 3000 for Travelling and approx Rs. 1500 - Rs. 3000 for some other Minor expenses.