Hello,
Without intermediate and any entrance exam score you can't join any college which needs both or one of them. You atleast need to qualify +2. If you have done then you can give the entrance exam to get an admission or look for college which can give you an admission on the basis of +2 marks.
For diploma there are screening tests or admission on the basis of +2 marks is done. So you have to go through rules to get an admission.
Government Polytechnic,Puri provides diploma in civil engineering, Mechanical engineering and electrical engineering. You must have your +2 marks to get an admission there.
Hope it helps!