Dear Shyam,
Section 494 falls under Chapter XX of The Indian Penal Code, 1860 and read as under.
494.
Marrying again during lifetime of husband or wife.
494. Marrying again during lifetime of husband or wife.--Whoever, having a husband or wife living, marries in any case in which such marriage is void by reason of its taking place during the life of such husband or wife, shall be punished with imprisonment of either descripttion for a term which may extend to seven years, and shall also be liable to fine.
Exception.-This section does not extend to any person whose marriage with such husband or wife has been declared void by a Court of competent jurisdiction, nor to any person who contracts a marriage during the life of a former husband or wife, if such husband or wife, at the time of the subsequent marriage, shall have been continually absent from such person for the space of seven years, and shall not have been heard of by such person as being alive within that time provided the person contracting such subsequent marriage shall, before such marriage takes place, inform the person with whom such marriage is contracted of the real state of facts so far as the same are within his or her knowledge.
AND the provision relevant to your query of section 198 of The Code of Criminal Procedure, 1973 read as under.
198. Prosecution for offences against marriage.- (1) No Court shall take cognizance of an offence punishable under Chapter XX of the Indian Penal Code(45 of 1860) except upon a complaint made by some person aggrieved by the offence:
Provided that-
(a) xxxx
(b) xxx
(c) where the person aggrieved by an offence punishable under section 494 of the Indian Penal Code(45 of 1860) is the wife, complaint may be made on her behalf by her father, mother,
(d) brother, sister, son or daughter or by her father's or mother's brother or sister. (or, with the leave of the Court, by any other person related to her by blood, marriage or adoption.)