Yes! UPSC allows the candidate to appear for the GS papers & the optional papers to be in different medium. So if you wish to write your GS in Hindi & the other papers in English, then also its possible.

For more information regarding UPSC CSE you can consider visiting the link below:

https://competition.careers360.com/exams/upsc-civil-services-exam

You have to make a good preparation for the examination. For the expert's opinion regarding the UPSC CSE preparation tips you can consider the link provided below:

https://competition.careers360.com/articles/how-prepare-for-upsc-ias

I hope this helps. Wish you a great eve!