To be eligible for the Combined Technical Services Examination (Diploma / ITI Level), candidates must possess a relevant diploma or ITI certification in their respective fields. The minimum educational qualification typically includes a completion of a diploma in engineering or technology, or an equivalent qualification from a recognized institution. Additionally, candidates should meet the age requirements set by the Tamil Nadu Public Service Commission (TNPSC), which may vary depending on the specific post. It is essential for applicants to verify the detailed eligibility criteria outlined in the official notification to ensure compliance before applying.