One of my friends was a student of the IEM thus, he had his reasons to make a choice among all the given options which might help you choose a college for yourself. 

Instead of enrolling for any college under WBJEE, you can try to go for IITs. If you have no luck there, then you should opt for government colleges such as CU, JU, and KGEC.

Talking about IEM, you should know IEM provides a good opportunity for the students with all the favorable benefits. 

Apart from this, Heritage Institute of Technology is not a good choice as the crowd of students doesn’t have any standards. Most of them are enrolled by the management quota. You may also go to other colleges like Techno Main Saltlake otherwise, you can also choose GCETT Serampore, near Kolkata, as it is also a good college. 

Calcutta University's syllabus is standard when compared to Burdwan University. However, it will not help you get good grades, instead, it will develop you in a better way. CU will provide the proper exposure as it is India's first state university with 150+ institutions. 

• If you study in CU and get a 50% or higher on your exams, you are considered to be a good student.
• Students generally choose Calcutta University over other institutions because there are few good colleges affiliated with universities. 
• The university has switched to a semester structure since last year. So, improved grades can be expected, with quality education. 
• More than 130 colleges are connected with CU. Not all of them are good. 
• Scottish Church, Bethune, Victoria, St. Pauls, Jaipuria, Vidyasagar, and Maulana Azad are just a few of the famous colleges affiliated with CU. 
• These colleges are available to you. You may expect high-quality education here. 

For achieving good academic scores, You can also enroll in other institutions such as Burdwan University (Chandannagar College is a great institution), Rabindra Bharati University, or private universities like Techno India or UEM. They are a bit expensive, yet they not only deliver good marks, but also placement prospects. So the choice is yours, if you want to go to CU opt for it or if not go for other colleges.

University of Calcutta and Kalyani Government Engineering College are both terrific colleges. There are certain precise points that draw out the best in these institutes.

• Faculty: Both the institutes have well-established faculty units. Kalyani Government Engineering College has around 9 faculty members in electrical engineering whereas the University of Calcutta has more than 12 faculty members in the chemical engineering department.
• Academics: The academics at KGEC is decent and the labs are well equipped too. The electrical department is one of the most relaxed branches and does not burden students with assignments. The students are provided with higher marks in practical papers in comparison to other branches. The major GATE rankers at KGEC are from the electrical engineering department.
• Higher Studies: Electrical engineering being a core branch provides better offers to you than chemical engineering. This branch makes available more seats in the government sector.
• Placement: CU provides more placement opportunities than KGEC. The 4-year B. Tech course even provides an almost similar level of placements and sometimes even better.

Since this concerns your career, you must take some time before concluding a decision. Whichever branch you opt for it is you who has to study for 4 years, therefore, make a wise choice that you would not regret later.