Practice with Mock Tests On Youth4work's site to improve your score in all the sections including the english section. CLICK HERE to reach to the Mock Test of IBPS RRB Office Assistant Main Exam.
Unfortunately 10 days are too less to improve your English section when it comes to competitive exams like IBPS PO RRB etc.
All you have to do at this point of time is to just go through the basics and look for some good questions for solving and for long term I would like to tell you to go through WORD POWER MADE EASY by Norman Lewis it will help for sure..