1. Your query is "Do we fall under Sapinda or we can file for divorce under HMA?",
2.The answer is Yes your marriage is illegal but is legal till it is declared by the Court as illregal/invalid against application filed before the said Court praying for declaration that the said marriage of your is illegal on account of being a Sapinda marriage,
3. Since your marriage has not yet been so declared as illegal/invalid it is a legal and valid marriage,
4. However, without complicating the matter, file a MCD if you two have decide to part ways,
5. The will be no requirement for mentioning your Sapinda relationship in your MCD petition. So, you need not bother for the same.