If increasing ground clearance is your major concern, then tyre upsizing will be of no help. This is because wiith bigger rim and and tyre width, the side profile has to decrease in order to maintain diameter difference of less than 3%.
An increase of 3% in ground clearance will practically make not much of a difference.
A more viable option for improving fround clearance is to use After Market Spacers. A decent quality pair of these would cost you around Rs 500/- approx. Use these and your vehicle should be able to get a better ground clearance.