Design is the core branch for M.Tech in Mechanical Engineering.
Regarding placements in Old IITs, it is very good.
MNCs like EATON, CATERPILLAR, AIRBUS, GENERAL ELECTRIC, ROLLS ROYCE, TATA MOTORS, CUMMINS, HERO, JOHN DEERE, HONEYWELL, MAHINDRA & MAHINDRA, GENERAL MOTORS, TVS & HUL visit the campus in Old IITs.
And almost everyone who needs placement get placed in any of the MNCs above.
The average salary (CTC) for M.Tech in Design goes around 7–9 lacs per annum ( Inhand salary around 55k – 65k) and that is good start for any M.Tech because promotions ahead gives you good amount after 5–10 years of service in this MNCs. The job is completely in R&D sector. So you need to perform well. It depends on what project you get in that MNC.