What bank is used by the Tier1s and 2s to pay the salaries? And are there any perks given by such banks?

You can't open salary accounts when you're not employed (you're on retainer).

I personally receive monthly retainer in a simple Bank of Baroda savings account (AQB 2k) and use a DBS Digisavings account (AQB 5k) for all external transactions. Fuss free.

From what I know, most firms use HDFC, Axis or ICICI