Dear aspirant hope you are doing well..

No your son is not eligible for neet ug exam without physics. Physics , chemistry, biology is the Compulsory subjects for neet ug exam..

• Minimum age of the candidates should be 17 years as of December 31, 2022
• Candidate should passed the class 12th  exam from any recognised brard with physics, chemistry, biology (PCB) or (PCMB) with English is the compulsory subject.
• Minimum aggregate marks: General category candidates must have passed the qualifying examination with 45% marks, while for SC/ST/OBC the minimum marks should be 40%
• Reservation policy for pwd (handicap) : 3% of the reservation will be provided to the Person with Disability (PwD) candidates.

https://medicine.careers360.com/articles/neet-eligibility-criteria-2022/amp

He can do his course from open university like Nios to become eligible or a regular course of pcb from recognised college/ university /school.

Hope it's helpful

Thank you