Hellow Rn,

Yes it absolutely possible to get a job abroad after earning an MBA degree from any good college not just from IIMs , because MBA opens a lot of job opportunities. In your case a job in London is also possible provided you equip yourself for that. Understand the job market there, do research on what type of  career you need , job position and companies you want to work for and such. Use job searching platforms like Linkedin and keep up a good network with London based employers, contact them, stay connected with the job offer updates of your desired company. Do internships with job offers upon completion in companies based on London. Acquire skills that your desired job demands by doing valid and highly accredited certificate courses from London Universities or any other reputed universities, to improve your chances and make you stand out from other job applicants. I hope , there is no need to explain on improving communication skills. Also more importantly look at the salary growth as a UK salary may seem good when you are in India but will  not match with the cost of living there, so choose wisely.

Hope this helps.