Visa on Old passort to travel to India

Hi Guys ,
My friends son has a British PP expiring on October 2018 . He is planning to visit india in August 2018 . He is aware that he has to renew his Son's passport before he travels to India .His question is his son has Indian Visa until october 2018 . Will his son be able to travel INdia with his Indian visa on old passport or he has to transfer it on his new renewed passport ,
Please advise ,
Thanks in Advance
Dip2018

Get a new Passport. Carry both old passport (which has Indian Visa) and New Passport with you. Old passport gets cancelled but Visa is still valid. There is no requirement to transfer, just carry both the passports with you.

Thanks for your Input .