What you want to do MBA/M.TECH has to be decided by the fact you want to do technical thing or management side of thing .
As for your current situation goes trying for MBA will be easy . First it does not require your knowledge of electrical concepts. There can be few question in admission interview . Second you have work experience but it is not in the field of engineering that you have done so it will be starting like fresher in job market . Call center experience and MBA will be better way for improving your career growth and career opportunities . I would have suggested you M.TECH but preparing for GATE exam will be difficult if you not clear with basics . even though GATE preparation make you go through concepts learnt in B.TECH , but if you are not sure then don't go for it . M.TECH is also good option but finally it is you have to do hard work . If by preparing for MBA exam you can get better result then go for it .
And be positive . There is nothing like loser . You are at least working . There are many who are not working even after completing their engineering . In every person's life there are setbacks . But to succeed you have to overcome these setbacks and all these negative feelings . You are still very young , have age on your side . If you will work hard then defenitely you will succeed .
You had appeared for both exam . So you would be knowing atleast which exam preparation can give you result . You already know both the exam pattern . You had to set goal and do hard work but has to be done smartly ....