Do payment banks maintain CRR and SLR?

Yes, the Payment banks have to maintain Cash Reserve Ratio (CRR) and Statutory Liquidity Ratio (SLR). At Least 75% of the demand deposits of the Payment Banks must be invested in statutory liquidity ratio (SLR) eligible treasury bills or Government securities. You can read about the Payment Banks- History & Regulations (UPSC Notes) in the given link.

Further readings:

1. RBI – Reserve Bank of India [UPSC Indian Economy Notes]
2. Download Indian Economy Notes For UPSC Examination