how i could get the latest firmware if it is not there

Hi, The ISP, bsnl provided the router to me, which is said to have rom 0 vulnerability and incorrect configurations by avast free scan.
How to upgrade it in router page? Is the router page connected with personal modem or it is different?
To be more clear, is the modem settings are automatically found in my router page or the page was updated by the ISp when it was bought for the first time.
I think that it is manually entered entries or selected menus from the router page.
Any idea of how to update.
Is rom 0 update different from firmware update , as i think that the configured settings save file is nothing but rom 0 . Please clarify.
The router is tdsl w32 type 2 model from teracom.I went to the page, and got page not found error.It is adsl2+cpe wireless router. Can i update the router page myself or has to get consent from ISP?

The firmware of a router has nothing to do with avast.
Please post in the correct forum next time.

The latest firmware for devices can always be obtained from the manufacturers website.

Hi Eddy
Thanks for the post. I could not find the manufacturer as his site links are empty with only past entries. No downloads.
But i found solution to rom 0 problem by downloading a simple program from this link and select update. It is a good site without any injection of tool bar and all that. I just updated. Eventhough my vendor name is not shown in router screen, it shows the router and i clicked the updates. Scanned with avast and it has resolved the problem. the link of the program is given for the users of this site who may have this problem of finding their router updates
http://www.simpleportforwarding.com/

Hi, the avast scan page is included