I am a Canadian Citizen and travelling to India from Canada. I have a lay over at Schiphol airport for 3 hours. Will it be possible for me to go outside to meet my university batch mate for half an hour. Or alternatively which will be the best place on the airport for us to meet.
As a Canadian citizen, you can enter the Schengen area for up to 90 days without requiring a visa, no problem there.
Your only issue will be connection time, so it might be best to arrange to meet your friend somewhere inside the airport so you will have a better chance of making your connection. You will still have to go through passport control to meet your friend.
Yes, you can. As @Greg Hewgill points out, you don't have a problem with visa. You do have to clear immigration and customs leaving the secure area to go landside, and clear security and immigration when going back airside. On busy days, this may take significant time.
Schiphol does have several restaurants/bars/coffee shops (regular coffee shops, not the ones you go to for weed) both on the ground level (entrance) and on the upper floors (above departures), so there's a choices of places to meet.
I do not recommend meeting outside of the airport, given that you only have a 3 hour layover, that would cutting it very thin.