Can someone please name college's I can apply if I got 50%ile in CAT

As you know that this is not a decent score so I would suggest to prepare again for the exam as this score will not give you the benefit to do an MBA, You can get a chance in a decent colleges through CAT if you little improve your score.

If this year only you are interested to get admission based on this score, Here are some colleges you can apply

ABV – Indian Institute of Information Technology and Management, Gwalior

Indian School of Mines. Dhanbad

Pondicherry University, Puducherry

SIES College of Management Studies, Navi Mumbai

Jaipuria Institute of Management, Jaipur

Vel Tech University, Chennai

Indian Institute of Health Management Research, Jaipur

Army Institute of Management, Kolkata

MIT School of Telecom Management, Pune

You can also use CAT Pathfinder Tool to check your other possibilities.

Https://bschool.careers360.com/pathfinder/cat

Good Luck!