For Platform#2 & 3 (see Pic 2) : Maybe if the extend it below Flyover, some track realignment is needed on the other side, they can be extended to a point just behind Jehangir Hospital
For Platform # 4 & 5 (see Pic 1): Track realignment is needed on both sides of the Platform if the want to extend it. They'd require a lot of blocks and extra work for extension
For Platform# 6 (see pic 1) : I'm not sure how much more length is required, but Electric Locomotive Trip Shed may...
more... pose problem for its extension.