Finally today after a long wait i got connected to some one at BLS (you know the very way people speak you can assess they are smart or dumb). The person immediately responded that if your son US Passport is still valid you can travel to India and you don't need to renew till 18 years of age but you need to make sure US Passport is renewed as and when due.
He said you may consider linking OCI to Canadian Passport but that is just an option (there is difference between i may do or i must do which he was pretty clear on)
I told him CGI messaged the same and he concurred.
Ideally i should have complimented him by saying you are working with wrong people
Lastly, I have an appointment for my son tomorrow with BLS, i may try and file Misc App but if they do any nit picking (bring this and bring that ) then i will just continue with OCI linked to US Passport.