As per the data available on the internet, there is no strict age limit to make a transition into the cybersecurity domain but the age-related issues are handled by each company’s policies on whom they will take and will also consider the age factor.
So, it's purely based on the company’s decision whether it will take in the employee above a certain age or refrain from it.
But on the skillsets side, if you hail from a computer or any other similar background then you can obtain certifications like CompTIA Security+ if you are a beginner, CEH (Certified Ethical Hacker) for intermediate, CISM (Computer Information Systems Manager) for advanced level, and CISSP (Certified Information Systems Security Professional) if you are an expert in the field.
If you are planning to make a career transition and are willing to acquire necessary skill sets, then do check courses on offer by Intellipaat:
or you can navigate through Cyber Security Certification by Intellipaat.