These are two things that may commonly be used in banking, but these two are different from each other. CRR stands for Cash Reserve Ratio. SLR stands for Statutory Liquidity Ratio. This is a type of reserves that banks have. The reserves of banks will differ a bit depending on what the bank can carry.
The form of CRR is usually cash, but it is different for the SLR. It will also come in the form of cash, but aside from that, there will also be other assets such as gold and other government securities. The effect of CRR is to make sure that it will control the excess money that may flow in the economy while in SLR, this will help meet the demands that depositors may have.