Social network at JIMS is involved in more engineers, scientists or high-tech background, while one at Said is more about finance and management. It is barely possible to rigorously define which school is better.
I agree that LBS is the most renowned B-school in UK. However, the brand name of Cambridge and Oxford per se is a selling point. Bill Clinton and his daughter, most of UK royals, over 20 UK premiers graduated from Oxford. More than 80 Nobel winners came from Cambridge.
Interview is conducted on a very personal basis. Each person has his/her own story in the essay. Generally speaking, go through your essay thoroughly, prepare answers for each story described in the essay interview committee may ask, and prepare good questions to ask at the end. Be confident, be yourself, present genuine self to the committee.
To be frank, my GMAT is not as high( <700), GPA is just 3.4. My academic performance is nearly nothing compared with that of exam experts. My working experience adds up to 2.5 years. Therefore, my background is not so strong as to share.