A bureaucrat like IAS, IPS, Must be Proficient and highly skilled in ENGLISH to handle top-level Doc’s and writings and discussions.
Most of the Upsc aspirants face this problem initially.
Read newspapers daily, don’t just give it a overlook read it thoroughly, be aware of the words, what the writer actually wants to convey.
Read any good magazine daily like yojana or kurushetra.
The following are Some of best tips
1. Read Editorials
2. Write Letters to the Editor
4. Write 100 words daily
5. Watch English Movies, Documentaries and TV Series
6. Think in English
7. Build your vocabulary
8. Read Government Scheme & Policy Documents
9. Solve Previous Year Question Papers