MEANS:
Suppose if the cut offs for the subjects are the following:
Phy- 1
Chem- 2
Maths-3
Then if u are strong in chem and score a lot in chem ( like 100) then u just need to get more than 1,3 in physics and maths respectively to clear JEE.
( BUT U NEED TO CLEAR SIMALTANEOUSLY THE TOTAL COMBINED CUTOFF THE THREE SUBJECTS)
So in a nutshell it means........score a lot in ur strong subject(s) then u just need to clear the single digit cut offs in other subjects.
PHEW!!! i Hope its clear now..