The information given in the question may be arranged as follows
Barun is taller than Sanjay.
Barun > Sanjay
Krishna is also not as tall as Bipul but is taller than Barun.
Bipul > Krishna > Barun
So according to above explanation the final arrangement is
Bipul > Krishna > Barun > Sanjay
So, Bipul is the tallest.
