Wedding Legalities
It is necessary to keep in mind that as a rule all marriages have to be compulsorily registered.
Those who undertake a civil marriage (No formal marriage ceremony) marry under the Special Marriage Act, 1954, do not need to take any further steps because in their case registration is itself the marriage ceremony. But in the case of all religious/ceremonial marriages, and they are the majority in India, the additional step of getting the marriage registered with the registrar of marriages is compulsory.
However, the non-registration of a marriage does not affect its legality and validity. Couples who do not register their marriages can be fined and any one giving false information to the authorities can be penalised with a short jail term. Even then it is always advisable to register a religious/ceremonial marriage because there is then proof of its legality and validity.
In matrimonial disputes it is not uncommon for one of the spouses to claim that no valid marriage took place. Religious authorities that solemnize marriages rarely maintain proper records. Once a marriage is registered with the authorities there is an assumption in law that a valid marriage took place.