Mani, CBSE has released a list of courses that a student can pursue after 12th in each subject. You can check the list at: https://news.careers360.com/cbse-releases-list-compendium-courses-students-pursue-after-12th . But to become an Soft skills ptitude trainer, you need to be good at Communication skills, Grammar, Vocabulary, etc. For that taking up English as  BA English can be helpful.  But if you want to become an Aptitude trainer for Quantitative Aptitude, then you need to be good in QA, Data Interpretation, etc. For this forte, you can pick up Mathematics. Having said that these skills be it soft skills or QA skills come with practise and what you study after 12th have got less to do with becoming an expert in these fields. It is practise that helps you master these skills. But just to answer your question, these subjects after 12th can help you.