Sagar's present age is 16 years.

Let Sagar's age be S six years back. Kunal will be 6*S/ 5

Add 10 year to both the ages (6 years until present day and 4 more)

Sagar will be (S+10) and Kunal ((6*S/5)+10)

using the ratio Kunal : Sagar as 11:10

((6S/ 5) + 10) / (S+10) = 11/10

Solving this we get S = 10

This was 6 years back hence present age of Sagar will be 10+6 = 16