its all depends on the deployment : (what RP fix the issue explained below )
cisco official guide :
others just in short :
If you are not already too far down the path of PIM-SM and IGMPv2, you might consider PIM-SSM and IGMPv3 instead. Unlike PIM-SM, SSM does not require RPs, eliminates group address collisions and provides a modicum of security against injection of bogus multicast traffic.
I am running IGMP V2 and Sparse mode multicast. Do i need an RP or not.?
Well, according to Cisco a RP is required for PIM-SM, more details here. The details show various ways of providing the RP.
Yes you will require to configure a RP, be it statically or dynamically via BSR