Pavan-1,  Is this occurring after an upgrade, or is this with the original dimms? Also, was this system in service when it occurred, or was this during an initial configuration? Just trying to clarify.  One of the things I would start with is taking the system to the minimum memory, which would be a single dimm in slot A1. Try powering up with only the single dimm in and see if the error clears. If not then try swapping the dimm in A1 with a known good one. If a known good dimm still fails to clear the error then we are possibly looking at the problem being the slot on the motherboard. You can also find some additional troubleshooting steps here - [URL] Let me know what you find.
I have Dell server PowerEdge R720 getting an error in DDR3, Error: Memory initialization warning detected DDR3 Training Failure - FPT - Write DqDqs DIM... and all,How o fix this? 
DDR3 training failure