Let start with Distance, correspondence or online master degree in engineering (M.Tech/ME). It’s a non-regular program you can do it from different place. Do check M.Tech distance education post for more details. Usually the requirement is that you must have a couple years of working experience and currently working with a list of mentioned companies. Duration of course will two to three years.
Part time M.Tech is offered in many top institutes and universities as a part of continuing education program. Classes usually held in evening and weekends, therefore you need to be in close premises of the institute. These courses are offered by many IITs, NITs, and other top universities. Please refer to M.Tech admission list and go around college by college to see if they offer part time master degree program. Eligibility usually is same a sponsored candidates, such as you must have a couple of years of regular job experience, a letter from your current employer saying that they are sponsoring you or have no objection on your studying while working in their company.
Last is Sponsored Maser degree in engineering program. As the name suggests, it is sponsored by your current employer company. You don’t have to have a GATE score (having one is really advantageous) to take admission into this program and relative less competition in institutes like IITB. Usual requirement for this program are a certain number of years of experience in the sponsoring company. A sponsoring letter from your employer. You will be admitted as regular candidate. Complete tuition fee and accommodation fee will be taken care by your company (or whatever agreement between you, company and institute is).
Pros of these programs are, you will get a higher educational qualification, hence will be entitled for promotions and salary hikes related to it (most of govt. organization offer these). Second biggest advantage is you are considered eligible for PhD in IITs and other top institutes.
Cons of these programs include no scholarship can be claimed during master degree. You are cannot apply for any other non governmental or industrial scholarship programs. Another big disadvantage of these programs is that you are not eligible to sit for campus placements during even if you are studying in IITs.