CBSE

You can get chemical engineering in private colleges with these ranks. Or, you can go for other courses in science field.

Min 45% required for General category student.

No, it is not mandatory to appear for the optional exam. The name suggests it is 'optional'.
You need minimum 5 subjects (including a language). But I'll advise you to appear and write CS exam also. In future, you'll have many fields open for you. It'll prove to be beneficial for you.
Work hard & good luck!

Dear,
You can get admission in it's my hope but there is a chance that you can get admission if they lower the cutoffs.

I guess the admission is based on JEE rank.
Tell me your rank then I can help you.

Admission is based on JEE rank.
And as far as colleges are compared, JUIT, Solan is better in terms of placement, academics and location.

Good Morning,
Yes, you can get admission in any of the college based on the cutoff criteria of the respective college. And one more thing first decide what you have take as in admission further.

Hello, hope you are doing well.
With this rank, you can go for a government college.
If I talk about Madhya Pradesh, you will get UEC, SITS Indore, IET DAVV (semi government), Jabalpur Engineering College, etc.
For other states, you will get a government college of that state.
Google it for your state government college.
All the best.