My Dad (86) lives in Troy. Hes lonely having lost Mom three years ago. He drives and no disabilities. Social activities?

Since he's not disabled, it's always good to do good for someone else. (see above! like reading to a child or listening to a child read and encouraging them. Schools love to have someone to help the little ones that aren't quite up to snuff and need a bit of extra help/love.) Deliver Meals on Wheels, doesn't take much time and is SO appreciated by folks that need food and some social contact.
Your dad may need help in getting started with the volunteering if he hasn't done it before.

Here's the Renssalaer County Department on Aging website. They have a calendar with activities for seniors under the Newsletters/Calendars/Events tab. If Aging Care strips out this link, just google 'activities for seniors in troy, ny' and it will come up.

Pam's got a good idea! How about a church service group, a reading to kids who need help, volunteering at local homeless shelter, vetersns group, does he have a cat?

Troy NY? He can go to the state legislature across the river in Albany NY and stare them down every time they try to something stupid. He will be quite busy for some time.