Which bank in India provides personal loan at lowest interest?

The rate of interest is dependent on
a) Amount Of loan
b) Tenure of the loan
It would not be that easy to pinpoint a single bank. Further, these banks change the rates quite often.
On a broader scale, here is what is charged for personal loans-
1. Union Bank- 12 to 14%
2. Bank Of India- 15 to 17%
3. Allahabad Bank - 13 to 14%
4. ICICI - 13 to 18%(depending on Tenure)
5. Bank of Baroda- 14 to 16%
6. Canara Bank - 16 to 18%

This is a broader comparison based on the respective websites. Please note that the websites are not always updated.

I don't know the best in your region but I would like to suggest you to not go for "The Bank Of Maharashtra" because I don't think its the best anywhere.