As you want to get the details of eligibility criteria for CET if you have taken supplementary exam for maths in 1st year PUC so here is the information of the same for you:

I am not sure

You may or may not get admission

If you want to get admission in BE courses in your state engineering colleges then I doubt.

Since many home state colleges deny providing admission after giving supplementary.

However you can appear for the CET next year answering all the subjects.