To apply in Italian University as an Indian student, you well need:

valid passport
Class 10 and 12 Marksheets (Class 12 result can be submitted later)
IELTS/TOEFL for English-taught course (may be waived)
Hey SOP, LORs, and CV
Portfolio (for design/arts)
Fly via university website or platform like Uni-Italia
Declaration of value (DoV) or CIMEA certification for document recognition

Yes, you can apply before class 12 results, and submit the final Marksheet once it's available. Admission will be provisional until then.

Once admitted, apply for the student visa (type D) and arrange housing, insurance, etc.