hi Baskaran,

normalised marks formula for TANCET

40 + (10/S) (R– M)

where M= Mean Marks or total marks obtained from the Part I, Part II and Part III sections of the paper divided by 3.
S= Standard deviation of raw marks
R= Raw marks or total marks obtained from Part I, Part II and Part III sections of the paper

hope this will help

all the best for your future!!!!!!!!!!!!!