- any invention that violates nature’s law.
- scientific theories.
- discovery of new form of known substance.
- mixture of two or more known substance.
- methods of agriculture.
- any medical procedures.
- plants or animals and their method of reproduction.
- soft-wares , algorithm mathematical or business methods.
- artistic works.
- topography of Integrated circuits (PCB designs).
- traditional knowledge.
- invention relating to atomic energy provided it falls in section 20 of atomic energy act.
As mentioned earlier the soft-wares cannot be patent but i would like to mention here that when a software forms an integral part of any type of physical application ( embedded , mechanical etc) then it can be patented.
Software can be patented in US though.