Hi Racheesh,
On autonomous access points you can configure multiple SSIDs on your access point if you don’t have multiple VLANs configured already. If your access point supports several radios (802.11a and 802.11b/g) then you can configure an SSID linked to one radio, and then another SSID linked to the other radio.
Anyways having two SSIDs configured to have access to the same network (VLAN) using two different Keys would not make sense because it would be like having a door with a lock that can be opened with two different keys, I mean, the clients that have access to the network on any SSID will have access to the same VLAN and the same resources.
But to answer your question, yes, the access point let you configure this, you only have to be aware that you will have the same encryption for both SSIDs, you can use different keys but since the encryption is set per radio and you are not using different VLAN you cannot select multiple encryption methods (like TKIP for WPA on one SSID and AES for WPA2 or WEP for the other SSID). To configure this just go to the Security tab > SSID Manager and add the SSIDs that you want; if you want encryption for WPA or WPA2 make sure you configure that first on the Encryption manager page.
Now, if you have already configured multiple VLANs on your access point and you want to assign two SSIDs to the same VLAN, this cannot be done and it is not even supported; the access point will actually throw you a message letting you know that the SSID is already linked to that VLAN.
Please go through the below link for configuration steps for SSIDs.
Here you go : http://www.cisco.com/c/en/us/support/docs/wireless-mobility/service-set-identifier-ssid/116118-configure-ap-ssid-ios.html
I hope this information answers your question.
