as per Art. 25 of the Constitution the sikhs are included in the definition on hindus though their marriage law and customary laws are differrnt and thus they find difficulties.
but probably the founding fathers of our Constitution have termed sikhs , jains , buddhists as hindus as all of them owe their origin to the Vedas and thus their underlying principle is same though thre may be minor variation in customs but special laws may well solve it. otherwis e our national integration will be at great threat.