I successfully establised the IPsec between 2 end points which consistes of ASA followed by a router on both ends. Then i configured the GRE Tunnel between 2 end and configured OSPF. No problem in OSPF Neighbour formation. But, couple of issues
When the Router reloads then the GRE is not establishing unless i execute the "clear xlate" on the ASA. when i clear the tunnel everything is working fine. Tunnel is back to normal
Inorder to overcome the above issue I change the default tunnel mode to "tunnel mode ipip". The tunnel is reestablishing automatically when the router reloads and i dont have to clear the tunnel. But the OSPF is not working when "tunnel mode ipip" is used.