At maximum you might be allowed to sit for the companies coming for mass recruitments, but i doubt if such companies would visit any of the IITs or NITs, since a student pursuing M.Tech is considered to have done a specialization already, therefore chances are less that such candidates would be considered by companies offering profiles in IT domain. However, you can apply off campus to companies like Accenture, Infosys, Wipro, TCS, Cognizant, they have their hiring windows open for freshers.