Ans. Requests need to come through respective governments / government agencies. There is no arrangement for training private individuals.
Q. 1. How can one get trained at NSG ?
Q. 2. How can one join NSG?
Ans. NSG is a deputationist force and therefore there is no direct recruitment. Please refer to link below for minimum requirements:- QRs for joining NSG There are also several physical and psychological tests to assess suitability.