Hello,
First thing first - is the car BS-4 Compliant
As per Supreme court - only BS-4 compliant car can be registered in. Been if the vehicle bought in other state and now needs to be re-registered in other state
In case if the vehicle in question is BS-4 compliant then 20% Road Tax will be applicable on the depreciated value
Exact price will be assessed in by RTO Officer, but to give an estimate - may check -
Depreciation Slabs for Road Tax
The URL covers for Karnataka, but is what close benchmark to what other states also do follows for calculation of road tax
Hope should help !!