Re: who would be the PIO for Thane city and where to locatew him
Each Public Authority has a separate PIO.
Normally if you visit the office of the Public Authority, there should be a board indicating who is the PIO in that office.
Alternatively just check up the website of the Public Authority and it will have a RTI link somewhere on the home page.
If all fails, just read the useful article by our member jps50 in the Guide Section: