The Indian equity benchmarks gained for second straight session on Monday on hopes of de-escalation of tensions between Russia and Ukraine as delegation of both the countries were set to meet at border of Belarus. The Indian benchmarks which plummeted sharply after Russian President Vladmir Putin ordered nuclear forces to be put on high alert recovered from lower levels with Sensex advancing as much as 1,491 points from day's lowest level and Nifty touching an intraday high of 16,816 after hitting low of 16,356.