The ruling TMC looks certain to retain power in West Bengal as, according to trends available for 284 out of 292 constituencies, the party was leading in 202 while the rival BJP in 77.
"Congratulations @MamataOfficial didi for landslide victory. What a fight! Congratulations to the people of WB," AAP chief Kejriwal said in a tweet.
Belying expectations of a tight contest, the TMC candidates appeared galloping to victory, and, if the current trends hold, the party will easily form its third successive government in the state.
In Tamil Nadu, the DMK was leading in 118 constituencies, the minimum required for a simple majority in the 234-member assembly, and its allies in 19, giving the grouping a comfortable lead as counting of votes progressed in the state.
Kejriwal also congratulated DMK President M K Stalin for this party's performance.
"Many congratulations to @mkstalin on a resounding victory in the Tamil Nadu assembly polls. I wish him a successful tenure and the very best in fulfilling the aspirations of people of Tamil Nadu," he said in another tweet.