Hello,

As firstly you have not mentioned name of any particular exam for which you are seeking this admission so, assuming that for JEE examination there are some bifurcation of seats done. Now if you are looking for the NIT and IIT than all 100% of seats will be given on the basis of your JEE main exam. Now in second category ie, the state of level of colleges, now in this you will find a lot of varieties such as in some government funded colleges in any particular state you will see that admission are done only on the basis of any state level examination and not by JEE score where as in private institutions it depends that colleges that how much seats they want to give through JEE exam but it is generally seen  that state level colleges mostly gives 10 to 15% of seats on the basis of JEE exam and rest through the state level exam, hope so it was helpful.

Thank you..