Section 135

YOU HAVE TO FOLLOW SECTION 135 AS YOU HAVE EARNED 5CR. IN A YEAR

ONLY CASE WHERE IT IS NOT APPLIES NOW IF,
1. YOU ARE A SPECIFIED IFSC PUBLIC CO.
2. YOU ARE A SPECIFIED IFSC PRIVATE CO.

in short answer is "yes" if u want detail see below

sec 135 says, it applies if a company satisfies the said criteria for "any financial year"

it shall cease to apply if the company does not satisfy any of the criteria for three consecutive f.y.

in your case
net profit
fy 2015-16 5cr
fy 2016-17 4cr

company has satisfied the criteria for the financial yr 2015-16 and so it needs to comly sec. 135 from fy 2016-17 since it has been only one year that the company does not fulfill the criteria

further if company does not fulfill the said criteria for fy 2017-18 and fy 18-19 it then would not be required to comply sec 135 from fy 19-20

in other words your company now in any case needs to comply sec 135 for upcoming fy 2017-18 & 18-19

So I need to spend at least 2% of Average Net Profit of last 2 years.

CSR = 9/2 * 2/100.