Questions

First nationalisation of commercial banks in India took place in 1969 and second time in 1980.

Orographic precipitation or Rain produced when moist air is lifted as it moves over a mountain range. As the air rises and cools, orographic clouds form and serve as the source of the precipitation, most of which falls upwind of the mountain ridge.

Some also falls a short distance downwind of the ridge and is sometimes called spillover. On the lee side of the mountain range, rainfall is usually low, and the area is said to be in a Rain Shadow. 

Sum of numbers in the outer circle in before Arc should come in inner circle patterns in the clock wise direction next Arc.

i.e, 9+6 = 15 comes in next arc of inner circle

7+3 = 10 comes in next arc of inner circle

In the same way, 4+2 = 6 comes in place of '?'.

Sulphur is an yellow element that stinks when burned.

From the hints,

Only two options for 1st and 2nd digits => 4,2 and 9,3 since it is single digits

Sum of second and third digit  = 10 

If 2 => 3rd digit = 8

If 3 => 3rd digit = 7

4th digit = 2nd digit + 1 => (2+1 =3) or (3+1 = 4)

Sum of all digits = 30

Let 5th digit be x

=> 1st possibility = 4 + 2 + 8 + 3 + x = 30 => x = 13 (Not possible since it has 2 digits)

=> 2nd possibility = 9 + 3 + 7 + 4 + x = 30 => x = 7

Therefore, the PIN is 93747