Answer:
(Fatwa: 927/866=B)
A Muslim can not marry a Shia girl. According to the beliefs of Isna Ashari Shias, as written in their books, they are out of folk of Islam; therefore Shia and Sunni can not marry each other. It is surprising how you performed the nikahand how your parents consented for the same.
As far as the credibility of certificate is concerned, you should contact the embassy.
Allah (Subhana Wa Ta’ala) knows Best
Darul Ifta,
Darul Uloom Deoband
