My foreskin doesn't pull back while erection.in normal condition i can easily pull it back.will i be able to have sex in such condition?

See your doctor: You may be able to have normal sexual relations, but you should get yourself evaluated - there may be a simple stricture or narrowing of the skin that the doctor can fix.

Check- up before: If you have had sex before and the foreskin has retracted during intercourse, you may have acquired an adhesion from an infection under the foreskin that is making the skin stick to the head of the penis as it enlarges. You may be able to pull the foreskin back without an erection since there is more slack and less resistance. Sex may be painful and cause bleeding if the foreskin rips.