I am a student of B.Tech Mechanical at VNIT Nagpur, so I can’t tell you anything about the Mechanical at SVNIT.
VNIT has a good reputation for its Mechanical. Most of the renowned alumni of our college are from this branch. Here’s a few of their names- Dr. Dinesh Keskar (President of Boeing India and VP of Boeing International Trading), Ashish Saraf (Vice President at Airbus), Hemant Karkare, Satyendra Pakhale and Sanjay Joshi. The faculty for Mechanical is good, and the department offers good lab facilities as well. The senior- junior interaction is also good at the department.
Though I do not know much about SVNIT, I expect that its Mechanical department must be at par with the one at VNIT. Do a thorough research before deciding between either of the colleges.