Firstly I will say it depends on your taste and preferences like if you ask me I m not much interested in reasearch work and thesis writings which are a part of m.tech and which to persuade some live industry experience which a job can provide but on the other hand m.tech improves your job packages if you haven't qualified Gate exam. So its a shear game of your taste if earning money is not important and your are really serious for higher studies and feeling the depth of any particular favourite subject of yours then go for m.tech otherwise a job.