It’s not as simple. They can be ‘z’ and be Portuguese related, if it is been carried over for generations. The ‘s’ standardization is from the XX century. The Portuguese reached India at the end of the XV century.
In places like Indian, these names have been carried over for many generations, so you can’t compare them directly with modern conterparts
Well, bear in mind that 8-10 centuries ago Castillian, Galician-Portuguese and the rest of Romances overlapped a lot, and they were a lot more similar to each other.
In places like Indian, these names have been carried over for many generations, so you can’t compare them directly with modern conterparts