The group stage of the 2012–13 Santosh Trophy features 16 teams: the 4 automatic qualifiers and the 12 winners of the qualifiers.^[1]

This article relies largely or entirely on a single source. (July 2022)

The teams were drawn into four groups of four, and played each once in a round-robin format. The matchdays were from 21 February to 26 February.^[1]

The top team in each group advances to the Semi-Finals.^[1]