hi Snehal,
please check authorization check at Bw side Tx - SM59.
go to sm59, ABAP connections, open your SRM Q to BW Q connections,
menu utilities-->test-->authorization check--> if you get any password error(due to multiple attempts, its locked) here then issue with your background user id.
Ask basis team help and ask them to reset the background user id(ALEREMOTE/BWREMOTE) password which is used while connecting RFC settings.
if authorization check is fine then please check defined port numbers for RSINFO and RSSEND at SRM and BW systems with help of basis.
hope it helps.
Thanks.