Hello Mahesh,
the commands are described in BGP command reference and provide the maximum number of imported paths for the VRF in the context of new event driven BGP VPN import feature,
http://www.cisco.com/en/US/docs/ios-xml/ios/iproute_bgp/command/bgp-c1.html#GUID-FC155DF9-4FFB-480F-9297-011FE81D3A20
However, to see 4 different paths on PE3 I think you still need to have PE1 RD <> PE2 RD for VRF test otherwise RR1 and RR2 by using best path choice will propagate only the VPNv4 advertisement originated by minimum IGP metric to iBGP next hop or if it is equal by min BGP RID [PE1, PE2].
The symptoms look like that PE1 RD = PE2 RD for VRF test.:
You should be able to see 4 different paths on PE3 even before applying those commands:
PE1 - RR1
PE1 - RR2
PE2- RR1
PE3 - RR2
Hope to help
Giuseppe