Test preparation

Yes, you can take classes for banking but it will be better if you take your 12th seriously because you have such subjects which need more attention.

I think if u want to do govt. job so b.tech is very good. if u are doing b.tech in mechanical;civil or electrical then in this branches many govt. job are available and many govt. bank have engineers work in banking sectors. so b.tech is good. if u will do b.com then u will need to go for MBA.because only b.com have no value. but u know well engineering have so much value. so go for b.tech if u are interest in it.

In CAT examination - you have 3.5 hours to complete the papers which are related to Mathematics, English – particularly grammar and comprehension more, logical reasoning and data analysis
Some of the Books recommended for CAT are-
1.How to prepare for Data Interpretation for the CAT TMH / Arun Sharma
2.Pearson Guide to Quantitative Aptitude and Data Intrepretation for CAT by Nishit Sinha
3.Quantum CAT by Sarvesh Verma
Get to know more about CAT on :
https://edudrona.com/common-admission-test-cat/#1464927769900-a0617f54-da37/?mref=tanu

start solving mental ability questions and also take out notes of EC

Hi Shubham,
Every institute has it's own course specific fee structure. In order to know the exact fee it would be always advisable to browse through the official website of the institute where you wish to apply.
Please feel free to discuss more.
Wish you luck.

Search on Google about specific country

prepare well and hard for Your boards then start JEE preparation . if u have fully prepared for boards then u got well in JEE also .

Not much. For IAS you have to prepare mostly the subjects like history, geography, and about administration (art stream subjects). Science is not much needed.

Yes Abhinav, for civil services one need to be a graduate.