Is that possible to find the share point site current logged In user information ?
I find many reference in net it show only current user (single user info only).
If I misunderstood your question, and you are asking about retrieving the number of currently logged in users, Bjorn Furuknap has previously written about this here:
Can you exmplain that what do you mean by this: "in net it show only current user"
Do you want to reterieve a single user info or all logged in user information?
If current logged in user information is required then you can use the above code as highlighted by James but in case you need all the logged in users then I am not really sure that you can get this via SP api.