what is the requirments for tourist visa ??

You have to apply from the CVASC in Milan or Rome. Don't forget to get those required documents needed:
1. a passport valid at least for six months and it should have sufficient blank pages
2. a filled application form with a recent passport size photo stuck on it
3. roundtrip airline reservation and hotel reservation
4. the original and a copy of your Italian permit of stay which should be valid for at least half a year. For those holding EU passport, a certificate of residence in Italy is required.