Colleges in Midnapore

No. GATE is not mandatory, but if you are thinking to do masters in India, then GATE is the best. Even if you spend a year in preparation, no problem, go for GATE.
Without GATE-
1.Career aspect: First thing you can't get into well reputed institutes like IITs, NITs, and some Govt colleges. When you done with you are M.Tech, the college from where you have done your masters is very important. It matters a lot in initial stages of your career. Most of the private colleges in India for name sake they are providing M.Tech degrees, but they don't have required lab facilities and well qualified faculty too, so what is the use obtaining degree from such universities?
2. Financial aspect:You have take care all financial needs by yourself. If you have cleared GATE, you will be getting stipend of 12400 pm,that too in Govt institutes you will have very less fees. Do you know? IIT Kharagpur tuition fee is 5k per semester, including everything ie food+Hostel+internet+medical etc. it comes out 33k per semester. You wont get such low fees in anywhere in India.
Actually any GATE qualified , if he takes admission through GATE in any AICTE approved colleges should stipend of 12400 pm, but it never happened in reality. You know its all government, no need to explain our system.
My advice, if want to do M.Tech, do it in well reputed colleges through GATE. If you are just thinking to get a M.Tech degree, then do it some private colleges.

In my opinion, opting, Haldia Institute of Technology(HIM) won't be a good option for you. I would recommend you to give one more chance and try to get a good B school or try to take admission in a management oriented institute. Anyways it's your call. Now coming to your question placements and faculties are good. Average package ranges from 2.53.2. As the batch strength is low there won't are many problems to a get campus or off-campus placements. You will get ample of time to prepare for any competitive exam like RBI Grade B or NABARD if you really want to do something out of the box. He will also provide you a various business platform to sell a product to a person. They conduct fests which allows you to expose your talents. Your college life will be awesome. But I will again recommend you to take admission in a Management oriented college which is situated in a metro city or any capital city as it will be beneficial for you in many aspects.