I've just completed my 30th birthday in January, can I apply for an acting course at National School of Drama?

For applying for the Diploma in Dramatic Arts at NSD in 2025, you'll need to wait for the official notification, usually released around March–April on the NSD Delhi website. The form is available online during the admission window. Since you're from Nepal with drama experience, you'll likely be eligible, but keep documents like experience certificates and performance records ready for submission.

Age limit should be 18 years and maximum is 30 years. The upper age limit is relaxable by 5 years for SC / ST candidates only. The preliminary screening comprises an audition or practical test and a final selection round at NSD Delhi. To get admitted to the National School of Drama course admissions, candidates must meet the eligibility criteria set by the institute. The candidate should pass Graduation in any subject from a recognised University. 

Your son is still too young at 12 to join the National School of Drama (NSD) since their normal courses have a minimum age criterion of 18 years. But he can begin by enrolling in NSD's Theatre Workshops for Children, held in various cities.