Need advice on the background criteria while applying for Internships

Hi All I am from a non-tech background and from a QA role from a service-based firm. I also have a 3 year career Gap. Since last year, I learnt relevant Frontend tech and have built couple of major projects around it. I am currently 30 years old and I am looking forward to change of domain of expertise. I want to apply for internships to get relevant industry experience in this field. I wanted to know the eligibility criteria (especially background specific) for the internship roles, as will I be considered as a relevant intern candidate, given my background ? Most of the Intern Job postings that I come across mention "Specific Batch Details" as their eligibility criteria. What other things should I be keeping in mind while for applying for internships. Any advice or suggestions from the community would be helpful. Thanks