To log in on netflix, it has to be an intel mac. The macs with the older chips will not work. If yours does not have the intel chips your only option (other than a new computer) would be to pick up a roku type device and stream netflix on your tv. They run about fifty bucks.
On edit: I sort of assumed you were talking about streaming instant watch.
“A state of war only serves as an excuse for domestic tyranny.” ― Aleksandr I. Solzhenitsyn