It is must to complete following step to do a marriage under Hindu Marriage act. If "saptpadi" not done so it will consider as a marriage under hindu marriage act. if this is case than in TV and films people done multiple marriages infornt of camera which is illegal
7 Ceremonies for a Hindu marriage.
(1) A Hindu marriage may be solemnized in accordance with the customary rites and ceremonies of either party thereto.
(2) Where such rites and ceremonies include the saptpadi (that is, the taking of seven steps by the bridegroom and the bride jointly before the sacred fire), the marriage becomes complete and binding when the seventh step is taken. State Amendments Section 7A Pondicherry: After section 7, insert the following section, namely:
(a) by each party to the marriage declaring in any language understood by the parties that each takes the other to be his wife or, as the case may be, her husband; or
(b) by each party to the marriage garlanding the other or putting a ring upon any finger of the other; or
(c) by the tying of the thali.