Agree with other posters that the place to start is with his travel coach. Also agree with other posters that your grandson need to make his own list of schools to pursue based on where he wants to be in life after college. Then work backwards to make that goal.
It is possible (my son is living example) that the schools your travel coach initially introduces your grandson to are not the best fit athletically, academically or other reasons. Don't get me wrong, my son's travel team was among the best in the country 10 years ago (won PG WWBA in 2008) when he was being recruited but the travel coach had no clue about high academic recruiting or engineering schools. We had to learn about that on our own. Travel coach did an awesome job of getting kids into programs at Univ of VA, South Carolina, Virginia Tech, VMI, James Madison, Univ of Richmond, William & Mary, UNC Wilmington, etc...but those were not great fits for my son. We had to do all the hard work of finding those fits then bring the travel coach in to help us with the "last mile" which was usually a phone call or letter to the Head Coach which led to offers.
The fact that he is getting interest right now is a great place to start. As more schools reach out, you'll get a sense of where he fits athletically. Follow that path, but be ready, willing and able to pursue or create other paths that your grandson (and his family) may want to pursue. Then bring that travel coach back into the mix to help close the deal.
As always, JMO. Good luck.