The off-spinning all-rounder is the first Kerala player to be selected for the Women's T20 Challenge.
The final match in Alappuzha was abandoned due to rains on Wednesday.
Akhil M S scored an unbeaten 31 as AGORC overhauled the target with more than three overs to spare.
Rojith Ganesh anchored the chase with an unbeaten 35-ball 30 as Athreya were home and dry with 20 balls to spare.
Veteran Indian cricketers Mithali Raj, Jhulan Goswami and Shikha Pandey, who played in the previous edition, are the notable absentees in the squads.
The match between AGORC and BK-55 CC was abandoned due to rain. The teams were awarded two points each.
Athreya CC scored a hard-fought three-wicket win over Masters RCC in another match.
Masters RCC beat BK-55 CC by 14 runs in the second match of the day.
The all-rounder, who represented Kerala in various age-categories, died in a road accident in Thiruvananthapuram.
Chasing a target of 165, Rohan and his opening partner Vishnu Raj added 132 in just 12 overs.