Dear Ajay,
During MRP run the system plans the alternative items based on the usage probability defined and in
the standard SAP your business requirement cannot be met directly.
Check these links to explore more,
https://www.sdn.sap.com/irj/scn/thread?threadID=474775&tstart=0
http://forumsa.sdn.sap.com/thread.jspa?messageID=7068228#7068228
Regards
Mangalraj.S