You really can't be 100% sure without knowing the internal dimensions.
I really recommend saving up some money and going with one of the fridges that are known to make great kegerators. And while you're at it, get one that can fit two kegs. You'll be happy you have the option. Even brand new, they're only like $200. Every homebrewer is super cheap about everything, and yet we'll spend sooooo much money on actually making the beer. Readjust your priorities for a few months and you'll have the money in no time.