Remarriage without getting divorce is a punishable offence with seven years’ imprisonment
As per Hindu Law, Christian personal law and Special Marriage Act(called as court marriage popularly), unless one dissolves a marriage legally, subsequent marriage will be void or invalid.
Even after getting divorce decree, one needs to wait till time for filing appeal passes and the decree is not challenged in a Higher court till that time.
Such marriage is void ab-initio and is not a marriage in eyes of law. The person so marrying can be charged with Bigamy.
Also, if a man marries a woman whose divorce case is running in court, he can be put on trial for Adultery as well apart from Bigamy,