If the scooty is gearless then he was having a valid lisence to drive,however the evidance that he was not driving rash and negligently shall be the deciding factor.
M V ACT- Age limit in connection with driving of motor vehicles.
No person under the age of eighteen years shall drive a motor vehicle in any public place:
Provided that a motor cycle without gear may be driven in a public place by a person after attaining the age of sixteen years.
Since 304 A, is not compoundable so the compromise will not be entertained,however the witnesses can give favourabe suppourt to get your son accquit of charges for not driving negligently or rashly.
You can file an application for exemption to appear in the court on educational ground but the discretion is purely upon court whether it may allow or not,. if prosecution will not raise objections the application can be allowed with conditions.(depends)