Ankit's daughter's mother---Ankit's wife; Ankit's wife's father---Ankit's father-in-law;
Father-in-law's daughter--- Ankit's sister-in-law. So, Sanvi is sister-in-law of Ankit.

Here in the given number puzzle, the given numbers follows a pattern that 

1 + 4 = 5 => 1 x 4 + 1 = 4 + 1 = 5 

2 + 5 = 12 => 2 x 5 + 2 = 10 + 2 = 12   

3 + 6 = 21 => 3 x 6 + 3 = 18 + 3 = 21 

Similarly, 

8 + 11 = 96 => 8 x 11 + 8 = 88 + 8 = 96  

Hence, the missing number in the given number puzzle is 96.

Southern state Karnataka has been ranked top among the states in the country in terms of manufacturing excellence, according to a study by apex industry body Assocham in 2017.