Career switching will be a problem with both these programs. it would depend on your post MBA career goals - which you need to be sure down to the level of position (salary)/company/geography. For example, Deloitte USA - Strategy & Operations Consultant - Chicago Office earning $120,000.
Have 5-8 such jobs in mind, and based on those jobs shortlist schools. i.e. see if your target companies offering your target roles and salaries have been to your target schools.

If you enter a program thinking you'll explore your opportunities later - it will become a matter of hit or miss. Most Indians coming to US/UK come dreaming of becoming a consultant or Product Manager but end up doing Analyst level work.
Explore the roadblocks in getting a job after graduation and visa issues in both US and UK. Make sure you are aware of the risks and have the risk appetite to make that informed decision.

P.S - What do you mean by IT - Finance? If you wrote a code for bank then your function will be IT. It's understandable that you may include Finance to differentiate from dozens of IT students applying to these schools - but that will work mostly with admissions not so much with recruiters.
Be very clear of your function, industry, geography both pre and post MBA

I don't know about the job opportunities in UK but its tough being an international student in USA. (I have been in US for 8 years and working for the last 4 years of those & i still don't have an H1-B visa)
You are an Indian in which case your job opportunities will be limited since you only get 1 year of work authorization (1 year OPT) after MBA program. If you do decide to stay in US, you will have to find an employer who is willing to file an H1-B visa for you. (There were 240K applicants for 85K visas in 2016 & the number of applicants is only going up)

So what are your goals?

Cass seems a better choice because of higher ranking, triple accreditation, international recognition & higher international mobility. Plus, London would be a ideal place for you considering your background in banking & financial institutions.

Meu,

"My goal is to go for higher role in the IT industry itself. I will be jumping from a techno-functional role to a managerial role in business unit/corporate unit." is a good start. But if I were a recruiter I think its fluff rather than specific.

I'd advise you - like I have earlier - to be as specific as you can. After all you'll be searching specific job roles in a specific company for a specific location.

Triple accreditation, ranking, higher reputation would mean squat unless you know what you'r looking for. If you want to work as Business Analyst in Amazon - Seattle then see if Amazon came to Cass or SMU or XYZ school. If not, then look for students who have graduated from your target school and have followed the same path that you want to pursue.

Cass and SMU couldn't be more different. UK vs US (work permits), 1 year vs 2 year (Cost + Internship), London vs Dallas (Target companies, Taxes, Location preferences?) .
It would be futile to contrast those here. Instead of getting a straight forward answer, look at your priorities, compare and decide accordingly.