Hi Shivlu
You "bind" vlans to the FWSM using the following command
On the 6513 chassis (NOT on the FWSM)
firewall module "slot number of FWSM" vlan-group 7 ( 7 is only an example it could be any number )
firewall vlan-group 7 "vlan numbers"
You need to do this on both chassis's
Aftrer this you can connect to the FWSM and create your interfaces etc.
Note that i'm assuming you are not using contexts ie. you are running in single mode.
You don't say what version of software you are using but have a search on Cisco web site with search string
"FWSM configuration" and you should be able to find the relevant guide for your FWSM.
HTH
Jon