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.

My hunch is that the above poster is slightly imprecise in the spelling but in India it's the Portuguese all the way.

Nope, just different origin centuries. He’s is right about current day portugal and spain, but these names have not been inherited from today’s portuguese.

Language and names evolve. And it’s been more than 5 centuries since portugal reached india

In my experience with Indians with Portuguese origin surnames have generally matched modern orthography.

A search on forebears.io seems to support my experience:

Rodriguez 1 in 2.6 million

Rodrigues 1 in 27 thousand

Rodrigues is modern Portuguese orthography.

Yes, it is.

Pinto, Dias, Gomes, Menezes, Mascarenhas, D'Souza, Coutinho, DeSa or D'Sa, Lobo are some other fairly common Portuguese influenced surnames in India, with the most in Goa and next most in Mumbai, but also occur elsewhere, since people move.