Hello aspirant!
Hope you are doing well!
Yes you can opt for ICAR exam for agriculture colleges
There will be 3sections in test paper- PCB/ PCM/ PCA/ ACB as per subjects.

Subjects: Physics, Chemistry, Biology, Mathematics and Agriculture. Candidates have to attempt only three subjects as per their selected subjects.

Since you have only 1 month, you can try giving it your best shot now! Go for smart work, rather hard . opt for previous year question paper and solve them