Is a PHD ( say in an IIT ) directly after B.Tech (without Mtech) eligible for regular jobs as Astt Prof / Prof in state/central universities

If somebody does a PHD ( say IIT ) after B.Tech (without pursuing Mtech) , will he be eligible for regular jobs as Astt Prof / Prof in state/central govt universities and other reputed private colleges ? Is Mtech mandatory for being eligible , and preferred over a Btech-PHD for a academic job ?