IDBI bank is one of the most successful private banks in India.they are having branches in many places and also ATM’s in many places among Kolkata.most importantly, almost all of their ATM’s work properly.second thing is their customer service is too good, even their security guards behave well with the customers.they don’t have a lot of staffs in every branches but all the staffs work properly to make it a good bank.you don’t need to stand in a long line to deposit or withdraw your money, they have different counters.