My bf(27M) and me(24F) are planning to get married but he is a marwadi bhramin and i am marathi.....

So any marwadi bhrahmins here can tell me if there is a chance for us to convince his parents? Because he has 3 4 sisters( 1 real and other cousins). And he tells me he will need to wait it out until then, but i cant wait for this much time, my father is 63 and diagnosed with Parkinsons, and i dont even have a brother so i need to get married till he is still independent. Idk does us marrying will make his sisters getting married difficult??