Professor has no interest in the topic of my research proposal
Yes, of course you can ask. And, depending on his personality and yours, you might be successful or not. Be prepared for the &quot;not&quot;, I guess. But you would be wise to give some deep thought to his suggestions, since he likely has more experience at this stuff than you do.
And one of the things you can ask about is why the professor doesn't advise you to follow up on your own plan. There might be some unstated reasons - though such things should be made plain. I think he owes you that much, at least.
But the best you can probably hope for is to be allowed to follow up on your own idea but with little help or guidance. If you are really new at this, then that guidance might be invaluable.
And fighting with professors seldom leads to successful outcomes.