int earned on fixed deposit whether part of turnover under GST

No, interest  earned on fixed deposit is not  a part of turnover under GST , 

In GST aggregate turnover means the aggregate value of all  taxable supplies  (excluding paid under RCM) , exempt supply, export of goods or service, or both , inter-state supply of  persons having the same pan to be computed on all India basis but   excludes  central  Tax , state Tax , UTGST  , IGST  etc .