Kazmi had reviewed films for `The Times of India` since 1987. She had also written a few books on cinema, the sources said.
Several Bollywood personalities expressed shock and grief over her death. "Was truly shocked to hear about the untimely death of Nikhat Kazmi...the TOI critic of several years...prayers and thoughts with her family. Death is always a reminder of life that most of us do not lead," filmmaker Karan Johar wrote on micro-blogging site twitter.
"The first ever review I read of `Refugee`, my first film, was by Nikhat Kazmi. She always pointed out the road to improvement to me. RIP ma`am," actor Abhishek Bachchan said.
"Tragic news. Extremely sad to know about the demise of Nikhat Kazmi, one of the most persistent film critics. Am sure wherever you are, it`ll be a five star rating, RIP. May God give strength to your loved ones," tweeted actor Akshay Kumar.
"The country lost one of the finest film critics today. RIP Nikhat Kazmi, may god give strength to your loved ones," filmmaker Madhur Bhandarkar said.
Actress Bipasha Basu said, "Life is so unpredictable. RIP Nikhat Kazmi."
Actor Neil Nitin Mukesh and filmmaker Mahesh Bhatt too paid tributes to Kazmi. "Nikhat Kazmi ji the one person who has always encouraged me. Wrote so beautifully and one film critic I respected a lot! May her soul RIP," Neil tweeted.
"Nikhat Kazmi was generous! Having come to terms with mortality she made it a point to look for something good in every film she viewed," Bhatt said. Actors Sonam Kapoor, Dino Morea, Arjan Bajwa, and director Ken Ghosh too expressed sorrow.