Dear Tarun
you are asking the "wrong" question. Question is:
1.) is the component produced by your own?
2:) is it part of a product which you receice
3.) which rule set do you would like to use?
It is very common (e.g. in US) that you will find on MSDS terms like: "Registered component" with some name but without CAS Number.
In terms of SAP EHS: as long as you know the chemistry of the "unknown" you are fine. In this case you would prepare REAL_SUB, use the "unknown" as part of composition and the use "Rule Sets". But if you have no "clue" about chemisty involved no rulke set and no human being can help.
Example: the component need to show up in either chapter 2 or 3 (and sometime 8). The component is used e.gf. to "calculate" labeling of the REAL_SUB (as well as classification): if you do not have the data to do so neither a rulke set nor a human being can help.
As long as you don not specify which rulke set you would like to run and which data you have on comonent without CAS number nobody can help you
C.B.