For gettting Nit sikkim civil branch you need to get a rank at least below 40000. Last year closing rank for other state general category students for civil engineering branch was 39865 so it is quite impossible for you to get a seat in nit sikkim with this rank. But you may get a seat in Nit arunachal in spot rounds. Last year in biochemical engineering closing rank for the home students in biochemical engineering was 522151. So you can try your luck in spot rounds of josaa. All the best. 

Greetings to you,

As per your CRL rank in JEE Mains 2019, you cannot get a seat in NIT Sikkim. Your CRL rank in very par and it clearly indicates that you have not cleared JEE Mains 2019. Thus, you cannot appear for JOSAA counselling. I would suggest you take a drop and give a shot at JEE Mains next year with the utmost preparation. Good Luck.