Hello Rajasekhar
Looking at some of the Cisco documentation on the subject, I see that the configuration process has changed slightly for IOS XR. The authentication is applied like so:
First, you need to define the key-chain:
key chain R1
key 1
key-string R1_Password
cryptographic-algorithm hmac-sha-256
commit
Then, you need to apply this key-chain to the OSPF area:
router ospf 1
area 0
authentication keychain R1
interface GigabitEthernet0/0/0/2
commit
This authentication command can be applied at the interface or the router ospf configuration mode. More information about the command can be found here:
I hope this has been helpful!
Laz