hi,

see since you have registered for 6 subjects you need to qualify in all subjects, if you dont give exam for chemistry in mark sheet it will be awarded as absent, after 10+2 you cannot get any good institutions for any course unless your 10+2 certificate is in complete. and during any job recruitment exam , let it private or government, it is strictly checked by the authority whether you have passed for all exam or not.

hope you may understand.