Dear experts,

I am working as a software engineer in one of the telecom industry in Bangalore. I have 2.5 years of experience as of now . Since my engineering days i was interested in doing m.tech and joining for lectureship. The financial conditions forced me to drop that idea at that moment. Now i have made my mind to pursue my dreams by cracking GATE-2016 and join any top institutions like IIT’s/NIT’s for Mtech. But i have few confusions in my mind.
Whether to do GATE preparation by joining weekend classes without quitting the job or Regular classes by quitting the job(i can handle financial things even if i quit job now) ? which is the best? What is ideal time in months needed for the preparation for an average kind of student in both cases?
I have the confidence of cracking in single attempt. But its always better to think about the negative side also; what would be the scope if i have to go back to software job after a gap , if my financial condition worsen at that time.
How difficult is to get the entry level lectureship posts ?
how is the growth in post of lectureship?
what could be the pay scale for the entry level lectureship jobs in any of the engineering university like VTU. ( as i found different answers when i browsed, i am asking here).
Any suggestions from the experts are welcome.

Thanks in Advance