You'll be able to host like 100 players , I used to host 150 players with 1gb.
But I had to restart every 5 hours , or it would crash.
Just upgrade your ram dude, it's cheap. With 2 gb you'd have no trouble.
I have two servers, one with 1 gb of ram and the other with 2, and the there are like constant 180 online players everyday on the first one and 100 on the second one (This one has 1 gb of ram)