This will change your nick to sriram
-NickServ- If this is your nickname, type /msg NickServ IDENTIFY
Now to register
/msg NickServ REGISTER pass123
NickServ- Your nickname is now registered under the hostmask [*n=root@*.maa.sify.net].
-NickServ- Your password is [your-password]. Please remember this for later use.