To get into Bucks You would need A level Qualifications or equivalent. Bucs require minimum GCSE Maths. Have a look at that standard of maths as its quite similar to the level of maths you use in a UK flight School.
This Paper is non-Calculator Standard:
http://filestore.aqa.org.uk/subjects...QP-G-NOV15.PDF
That paper would be a minimum expected knowledge in maths. I would say grade B min in that.
Lufthansa requires you to be able to speak german to a certain level. So unless your good at that you will struggle.
Do you have access to a European visa? Not really clued up about Indian Visa system and what one you would need.