What are requirement to Constitutes a valid marriage?

The requirement to constitute a valid marriage are: 

1). Parties must freely and voluntarily consent to marriage as per section 13 of the law of Marriage Act, 1971.

2). Parties thereto must be of minimum age required to marry as per section 16 of the Law of Marriage Act, 1971; 

3). Marriage must witnessed by at least 2 competent witnesses; 

4). Parties must not be within a prohibited relationship; 

5).Either party must not have another subsisting marriage; and 

6).The marriage should not be of a temporary nature or for a limited period.