Welcome to the forum..
Is your Phone Network locked ?
Availability of Update depends on Region /Product Code.. also if the phone is Network locked, then the update is possible only after an approval from the Operator...
Give it a try thru' Nokia Software Updater as well as the OVI Suite..(..sometimes one works when the other doesn't..).. If still it shows NO UPDATES.. then you will have to wait and keep on checking.. Its not possible to Force update...