The Varanasi-set movie, which stars Richa Chadha, Sanjay Mishra, Shweta Tripathi and Vicky Kaushal, revolves around a bunch of characters trying to escape their small town moralities.
The 52-year-old author took to Twitter and lauded Ghaywan, saying she "didn't have high hopes" from Hindi movies but "Masaan" surprised her.
"I didn't have high hopes about Hindi movies as most of them were musical melodrama. But 'Masaan' made me speechless. I salute Neeraj Ghaywan," she wrote.
The director replied, "overwhelmed! Thank you so much!"
"Big heroes of Bollywood should learn how to act from young actors of Masaan," she wrote later.