You can employ him on a retainership basis. There is no age limit for retainers. I remember we used to give employment to many retired officers on a retainership basis who were in the age range of 60 to 86 years. The PSAR Act 2005 gives an age limit of 65 for private security guards.
The regular age of employment is what we are talking about, only concerned with PF, gratuity, ESIC (say all compliance). So kindly go ahead and give employment to deserving candidates.
Regards,
Capt Rajeshwar Singh