I carried out an istikhaara for a marriage proposal and Alhumdulila received a positive sign but my father disagreed to the matter proceed any further. If a positive indication is received from istikhaara then does this mean that the marriage will actually take place regardless of any obstacles which maybe faced?

All perfect praise be to Allah, The Lord of the Worlds. I testify that there is none worthy of worship except Allah, and that Muhammad is His slave and Messenger.

It is unlawful for you to marry a person whom your parents do not approve of, even if you find satisfaction in marrying him after performing the Istikhaarah prayer.

Know also that it is not necessary that your marriage to him be realized only because of your good feeling towards him after the Istikhaarah. Finally, the Istikhaarah is the right thing to do. Now that you have done it, be certain that only that which is good will befall you in this matter. This might be that you marry this man. Similarly, the good might be that you marry someone else.

For more benefit on how to perform Istikhaarah and how to supplicate Allah, please refer to Fataawa 172573, 81434, and 82964.

Allah knows best.