How to migrate to Bsnl FTTH online ?

Is there any option to Migrate my Existing plan BBG Combo ULD 1199 to FTTH plan online ?

Should i change my adsl modem for FTTH ?

I saw some cool affordable plans in FTTH, i think those plans are better than 1199 plan with unlimited Free calls.

There is no option to migrate to FTTH plans online AFAIK. You need to contact your local bsnl exchange and ask the JTO/JE present about the feasibility of FTTH in your area. They will give you the full details.