Marriage to a Hindu, Permissible!

It is noted that is not permissible for a Muslim to marry any non-Muslim woman unless she is one of Ahl Al Kitab (Jews or Christians). The evidence for that is the saying of Allah,

Made lawful to you this day are At‑Tayyibat [all kinds of Halal (lawful) foods, which Allah has made lawful (meat of slaughtered eatable animals, milk products, fats, vegetables and fruits)]. The food (slaughtered cattle, eatable animals) of the people of the Scripture (Jews and Christians) is lawful to you and yours is lawful to them. (Lawful to you in marriage) are chaste women from the believers and chaste women from those who were gi
ven the Scripture (Jews and Christians) before your time when you have given their due Mahr (bridal-money given by the husband to his wife at the time of marriage), desiring chastity (i.e. taking them in legal wedlock) not committing illegal sexual intercourse, nor taking them as girlfriends
” (Al-Ma’idah 5:5) 

So Allah has permitted the Muslim men to marry chaste Muslim women and chaste women from among Ahl Al-Kitab. 

Imam Al-Tabari said, commenting on this verse, “The saying of Allah, ‘and chaste women from those who were given the Scripture (Jews and Christians) before your time‘, means free woman from among those who were given the Scripture, i.e., the Jews who follow the Tawrat (Torah) and Christians who follow the Injil (Gospel).”

Thus, it is not permissible for a Muslim man to marry a Magian (Zoroastrian), Hindu, communist or idol-worshipping woman, etc. The evidence for that is the verse in which Allah says: 

And do not marry Al-Mushrikat (idolatresses) till they believe (worship Allah Alone). And indeed a slave woman who believes is better than a (free) Mushrikah (idolatress), even though she pleases you…” (Al-Baqarah 2:221)

You are only allowed to marry her if she embraces Islam wholeheartedly, for the sake of Islam not in order to get married with you. If she insists on Hinduism, then you should fear Allah and not marry her. Be sure that Allah will compensate you with something better. The Prophet (peace and blessings be upon him) said, “Whoever gives up something for the sake of Allah, Allah will compensate him with something better.