What is the placement scenario in communication systems and VLSI at IIT Patna?

I have heard that in old IITs like Delhi , companies come and prefer MTech students over BTech. In IIT Patna its opposite many companies do not allowed MTech people to sit for their exam. Some companies take both BTech n MTech students but they pay lesser to MTech students than BTech for the same job. I don’t have much knowledge about companies coming exclusively for mtech . For Btech companies like Tektronix , Texas Instruments ,synopsis , Isro etc visit the campus in the mentioned field.