I had completed 12th in 2017 and Bachelors in 2021. Am I eligible for admission in any college?

Short answer is YES you are eligible for admission in any colleges. you can apply for any college for  undergraduation degree and Diploma courses. but it will vary according to the institution you're applying to, if they are allowing,   because some of institues are demand low gap year . and some go

Yes, you will probably qualify for higher studies, like a master's or postgraduate diploma, even with a gap in between your 12th and bachelor's degree. Most universities appreciate that one might need time for personal growth or work experience before pursuing further studies.