About Marriage Law

Dear Sir, My name is Rahim. I am planning to marry on 2020 Jan 10. I need a legal advice from you. According to Indian law, If the qirl wants to marry on 2020 in the month of January . In which year she should be born. What should be her date of birth. Her actual DOB is August 7, 2002. Is she eligible to get marry in 2020 January? As per her marriage date, Could you please let me know the exact Date Of Birth . So that we can avoid child marriage. Thanks, Rahim