Hi Karan,
It is good that you are already aware of the modules of SAP (Technical & Functional), if you are interested and have a inclination in technical work then the Technical Module will be good but if you prefer and like a functional module then you may pursue that too.
With regards to BI and ABAP, BI module involves importing data from different repositories/databases and generating business reports for different stakeholders of an organization, if you like working with databases and doing data modeling etc then BI is something that you would enjoy. ABAP is a field where one is required to create/update/modify T codes used in SAP. There are many people who don't have a engineering degree but still are doing good in Technical modules in SAP and non SAP related work. You can learn BI and ABAP and your degree should complement it. Remember, you should try to learn things clearly and to a greater depth if you want to stand ahead of others. Many people learn things but don't build the skills that makes someone an SME and Implementer.
Cheers,
Nagarajan Viswanathan