Hello Ayush sir, 

Sorry to say sir but with the rank of 209250 in JEE MAINS your son will not be able to get a seat in DTU. The minimum rank required to get admissions into DTU is under 25000 for CIVIL and MECHANICAL. Even he will not be able to get a good government college with this rank. If your son has written other examinations like MHTCET, UPTU, MANIPAL, VITEEE, SRMEEE, etc, then i would suggest you to take admission through other examination. 

I hope you will find my answer helpful. 

All the best.