As per the question,
Statement I: Keshav > Shailendra > Rakesh
Statement II: Keshav > Ashish > Shailendra
Statement III: Madhav is the tallest
Combining all the statements, we get the order of heights in increasing order as follows: Rakesh < Shailendra < Ashish < Keshav < Madhav
Hence, the required answer is (2).