Nexus 7010 is the only chassis whcih has optional air filter. The filter locates at the bottom. On the picture attached you can see not the FAn but air intake. I think that is the pin to release air filter once the screws are made loose. See the procedrue below
Thanks for the reply.
I went thru the image of the 7010 and saw that the optional air filter seems to be covering the pin. Is it used as some sort of support instead rather than a release pin.
I had logged a TAC case with cisco and below is the reply I had gotten from them.
"Regarding the push-pin, this is use to detect whether the air filter is present. YO can check the status with the "show env" command."
Hope this help others in the future as most have have helped me.