Despite being longer in length, Tejas mk2 will have lesser empty weight than mk1 as per DDR. Link👇
https://delhidefencereview.com/2019/02/23/tracking-the-tejas-the-tejas-mk2-grows-a-pair-becomes-the-medium-weight-fighter/
Amit Kashyap also told the same in yesterday's video. So with same engine...