There is no better college of the two because both are equally good in terms of placements and faculty. Both have their pros and cons. But here I will just cite some pros of both colleges that might help you make a better decision. 

Pros of GIM

• Offers a comprehensive learning experience 
• Many student-operated clubs and committees 
• Fun-filled campus life 
• Top-notch infrastructure
• Better placement opportunities and exposure to industry projects
• Smaller batch size therefore a better chance to grab good packages and lesser competition.

Pros of KJ Somaiya

• KJ Somaiya a location advantage for students from Mumbai, Maharashtra 
• better ROI

For more details you can talk to the alumni of the respective colleges.

Although all the B Schools you mentioned are very good, the one I would personally recommend is FORE. Some points that favor my recommendation are

• Location-based crowd: All the other colleges you mentioned have students mainly from Mumbai. But FORE located in New Delhi, the heart of the country has students from all over India.

• Placement: Here’s a tabular comparison of the average and highest CTC of the colleges. 

• Fees: 

GIM: ?18,31,200

FORE: Rs.16,98,000

KJ Somaiya: ?9.59 Lakhs (one year)

SIBM: INR 3.53 L - 16.62 L(for 2-3 years)

FORE offers industry oriented certifications and International Immersion Program. So looking at the overall picture we can say all 4 colleges give each other tough competition but FORE takes the lead.