Originally Posted by Shreeni0403

I am not sure what pitch chain FZ has but have a simple solution for you.

If the chain pitch is 520 i.e like Karizma, Pulsar 200,220,180(UG4) then you can opt for P200 rear (38T), P220 DTSi (36T), P220 DTS Fi (37T).

If the chain pitch is smaller as in Unicorn and other bikes then you can opt HH Ambition (38T)

Thou am not sure about fitting on sprocket hub but customizing the holes wont be a problem.