Hi,

I hope you are doing well.

Yes, don't think at all that this gonna effect your placements. Even students who fail in graduation years are considered for placements, So this thing should not affect your level of confidence at any stage.

You might get a question from the interviewer that why you took a gap year after 12th, just give a genuine reply that why you actually took a gap year, is it because you were preparing for exams or you were ill, you were not sure which course to choose or any xyz reason for which you took a gap year. A gap year after 12th is not at all hindrance in any of the placements.