According to Wikipedia:

Rashtra Kavach Om received negative reviews from critics. Ronak Kotecha of The Times of India rated the film 2.5 out of 5 stars and wrote “Rashtra Kavach Om is just as unreal and outlandish as its name, if not more. But if you’re a diehard Aditya Roy Kapur fan then maybe this mission isn’t all that doomed for you”. Nairita Mukherjee of India Today rated the film 2 out of 5 stars and wrote “Aditya Roy Kapur’s glistening biceps, though impressive, may not be strong enough to hold the weight of this strictly average actioner”. 

Dishya Sharma of News 18 rated the film 2 out of 5 stars and wrote “Aditya Rao Kapur turns into an action hero but fails to pack the punch”.

Sanjana Jadhav of Pinkvilla rated the film 1.5 out of 5 stars and wrote “Rashtra Kavach OM is a messy and unsatisfying two-hour action film that has too many WTF moments to keep up with”. 

Shubhra Gupta of The Indian Express rated the film 1.5 out of 5 stars and wrote “Aditya Roy Kapur-Sanjana Sanghi starrer is yet another addition to films Bollywood has adopted as a safe bet these days, with a hero who has patriotism oozing out of his pores”.

A critic from Bollywood Hungama rated the film 1.5 stars out of five and said Rashtra Kavach Om is a poor show and will have a very tough time at the box office. Nandini Ramnath of Scroll.in rated the film 1 out of 5 stars and wrote “Kapur’s Om is most alive when he’s yelling the battle cry “Jai Bhavani!”  with the fervour of a Shiv Sainik”.

Saibal Chatterjee of NDTV rated the film 1 out of 5 stars and wrote “Since there is no defence system that can reverse the ill effects of bad writing, Rashtra Kavach Om is never in with a chance of putting two sensible ideas together”.