Indian Bank is an Indian state-owned financial services company established in 1907 and headquartered in Chennai, India. It has 20,661 employees, 2594 branches and is one of the top performing public sector banks in India.

For getting Back your User Id you may First Contact to the Customer Care of the Indian bank then they Should Send you the User ID on your Regstered Mail Address the Customer Care Number of the Indian Bank is As Follow

Customer Care Number
1800 4250 0000

Corporate Office - Phone Number
044 28134300

Corporate Office - Postal Address
Indian Bank, Corporate Office,
PB No: 5555, 254-260, Avvai Shanmugam Salai,
Royapettah, Chennai - 600 014

Or you may Also contact to the your Home branch the Contact Detials of your branch of the Indian bank you may get from the branch Locator Section of the Indian Bank

For your convince Here I am giving you the Snapshot of that page

Indian Bank branch Locator