State Bank Of India, The largest bank of India but you face many problem in the Bank.
1) Phone banking; If you lost your credit/dabit card than not good reply to call centers.
2) When you are going to branch for deposit cash then you face many rush in the branch and Internet is not working properly in all branches.
3) ATM Service; Many ATM s are cash less or if lost your credit/dabit card, Recover in one month. So this is the largest bank of India.