Lalzofolai, Zico and Ronald scored for Mizoram in the Group A match which was locked goal-less at half-time. Nasaruddin pulled one back for Kerala, who were also the runners-up in the last edition.
In another Group A fixture, Maharashtra got the better of Uttarakhand in a tightly-contested match.
Allan Dias (37th minute), Mohammed Shabaz (43rd) and Santosh Koli (88th) scored for Maharashtra.
For Uttarakhand, Ashok Singh (19th) and Sher Singh (68th) found the target.
Ten teams have been divided into two groups of the five with the top two sides from each group advancing to the Semifinals.
Group A has defending champions Services, last year's runners-up Kerala, Maharashtra, Mizoram and Uttarakhand. Group B consists of 31-time champions West Bengal, Punjab, Railways, Goa and Tamil Nadu.
The final is slated to take place on March 9 at the same venue.