Coaching is not essential for Civil Services Examination preparation; if you can understand the requirements, you can prepare with self-help.
Electrical Engineering has produced many top rankers that include names like Mutyala Raju Revu (AIR 1, CSE-2006), Supreet Singh Gulati (AIR 2, CSE-2007), Prakash Rajpurohit (AIR 2, CSE-2009) and Prince Dhawan (AIR 3, CSE-2011).
The recent changes in Main Examination pattern have changed the rules candidates use to follow for optional subject selection. Still, this is one of the important decisions one has to make while preparing for Civil Services Examination.
In new environment, most of the candidates contemplate with idea of keeping their own subject as optional subject. We suggest you to have a look at the syllabus and previous years’ question paper to understand the level and current trends and if you feel it is manageable, then it is okay.
It is a good optional subject and if you are confident, you can consider keeping it as optional subject.
The following article is little old but would provide you some ideas related to the query you have raised: