Dear Sir/ Madam

My daughter passed 12th CBSE exam this year with Physics, Chemistry, Biology & Multimedia. She would like to appear for Mathematics as additional subject and I need to know the following
1] The procedure
2] If she appear for Mathematics and pass, can she go for engineering?
3] If she need to write both 11th and 12th exam for Mathematics ?
4] If the answer for the above question is Yes, can she write both the exam's in one year ? [next year]

Thanks & Regards

A.R.PETER
NIZWA
SULTANATE OF OMAN