Thanks Mallik,
The issue was with the connection only. The Universe should be connecting to a BEX query only, not a multiprovider. But somehow due to BW access issue, the BEX query was not available in the connection pool. Hence the BAPI connection pool was showing the Universe connected with Multiprovider itself.
Once we provided the proper permissions to the BEX query to be visible in BAPI connection list, and connected the Universe to it, all the objects went fine.
Thanks for all your help.
Regards
Rahul