I see that you are confused between power electronics and power systems in mtech. Considering both i would say that power electronics is slightly, just slightly tough than the power systems. But if you are serious about mtech then you should go for power electronics, as there are new researches inn it. But if you ask for job wise then power system is slightly better in govt. sector enterprises. So it completely comes to your interset,but i would suggest to go for power electronics.