2nd Pic - Trisha Krishnan. Yes she's the new heroine to Nandamuri Balakrishna now. If not in Tamil, she has now acted opposite all the 80's & 90's Superstars in Telugu industry - Chiranjeevi, Venkatesh, Nagarjuna & Balakrishna.
3rd pic is Rang Rasiya.
I guess you meant 4th pic, it's Priya Anand. She was there in English Vinglish.