Which college am I more likely to get with a rank of 31918 in JEE?

Hello, Most likely, you will get a government college of your state except NITs and IIITs. You have good rank and generally, government college's rank falls into this category as well. Go for good government colleges.

Please visit this link. This is a college predictor and I hope this will help you to choose the right college- https://www.google.com/url?sa=t&source=web&rct=j&url=https://www.shiksha.com/b-tech/resources/jee-mains-college-predictor&ved=2ahUKEwie-7mvrITiAhWz73MBHYuID8oQFjAAegQIAxAB&usg=AOvVaw1N9BzFt