law: 42. Certain decisions to be according to custom or personal law.-
  (1) Where in any suit or proceeding, it is necessary for any court under this Act to decide any question regarding succession, inheritance, marriage or caste or any religious usage or institution, any custom (if such there be) having the force of law, orany personal law, governing the parties, or the property of the parties to such suit or proceeding shall form the rule of decision except in so far as such custom or personal law has, by legislative enactment, been altered or abolished.
  (2) In cases not provided for by sub-section (1) or by any other law for the time being in force, the court shall decide the suit or proceeding according to justice, equity and good conscience.