It all depends upon your preference as the infrastructure, faculty members differ from department to department. One of my friends, who pursued his M.Sc in Chemistry from KU, told me that it’s really good.

• The faculty members are very kind, helpful, and amiable. They are always ready to assist you in any query. 
• Moreover, the building is old but it consists of sufficient equipment and better infrastructure.
• Kalyani University is the largest state university in West Bengal. Here, you will experience the lush green campus where you can freely roam around.
• The central library is big and well-equipped with textbooks, journals, and reference books. Student life here is also very good.
• The teacher and student interaction are quite healthy. 

Overall, Kalyani University is a good university and I would suggest you go for it if you are thinking of taking admission to it. 

After doing some research online about these institutions, with my limited knowledge of JGEC & KGEC, I am writing this response.

• Given that they are government colleges, both are great institutes to begin your career.
• They never promote or market themselves in the way that other institutions might (Return on investment involved).
• Although JGEC is underestimated because it is located in North Bengal, it does not receive the same level of exposure as KGEC or BWD university.
• KGEC is known for its technology/IT courses, while JGEC excels in the core departments.
• TCS is a regular for KGEC in terms of recruitment, whilst CTS favors JGEC.

Lastly, I can say that you can opt for any of the colleges, it will be a good step ahead in your career. Choose which suits your requirements the best.

Kalyani University is a very popular institution and pursuing an engineering degree from this university has its own pros and cons. Some of my friends studied there and here are the things I got to know from them.

Pros 

• This institution is owned and run by the government. The complete fees for your 4 years of graduation is less compared to other private colleges.
• The faculty of this college is very good and all other staff members such as lab assistant, office staff, canteen staff are very helpful. 
• The university also hires some external professors having years of industry experience to teach and guide the students. 
• This gets them accustomed to the corporate culture. 
• The total number of students in this department is less so you will always have the chance to interact with your professors.

Cons

• One of the biggest demerits of this university is that it doesn't have a proper placement cell in its campus. 
• Securing a job offer is tough, and you have to take the initiative yourself.
• The infrastructure of this college is average. The computer lab, electronics lab, instrumentation lab don't have adequate facilities. 
• The campus is located in a remote area. But the transportation facility is okay.