Anyone but you can decide what’s best for you. Only you can make an informed decision based on your expectations and ability to take risks. However, I will recommend you opt MSc in Finance if you are sure about your career in the Finance sector and are ready for Finance roles. In case you are not very sure, try contacting some seniors from the institute or doing some research on LinkedIn. If even after researching your gut is not very sure about Finance then opt for a core MBA only. 

By taking MBA, you can test your inclinations throughout the first year and find out if Finance is really your cup of tea rather than joining an MSc and regretting it later. A slight comparison between the 2 courses is given below

Brand: Brand-wise MBA/PGDM of Sydenham is a much older and bigger name in comparison to the MSc Finance of JBIMS.

Scope: The MSc in Finance at JBIMS has a much greater scope than MBA from Sydenham.

At JBIMS, both MMS and MSc Finance offer similar opportunities. Although many students exclusively target MSc. In finance, there tends to be an obvious preference for MMS. So in the near future either MSc Finance could be a separate course from MMS or even be discontinued. Not much can be said about this. So the only factor you should consider while deciding is your own inclinations.