Is it require the different license from symantec endpoint license fro the installation?

Yes it require the different license.

Check

https://www-secure.symantec.com/connect/forums/does-symantec-network-access-control-121-part-sepm-licensing

Installing SNAC 12.1 in conjunction with an existing installation of Symantec Endpoint Protection Manager (SEPM) 12.1

Yes you need to seperate licenece

See this

http://www.symantec.com/connect/forums/snac-status-not-licensed

http://www.symantec.com/connect/forums/snac-license-file-0

Yes, you need a different license. The components are already there but it needs a license to get activated.

Activating or importing your Symantec Endpoint Protection or Symantec Network Access Control 12.1 product license

http://www.symantec.com/business/support/index?page=content&id=HOWTO81006

If company purchase the license of 12.1 when i upgrade the clients in 12.1.4 will it auto upgrade?

If company purchase the license of 12.1 when i upgrade the clients in 12.1.4 will it auto upgrade?

Yes you can use sep 12.1. same licenece key in SEPM 12.1.4

yes, you can upgrade to the SEP 12.1 RU4

Hi

If you are looking to activate the SNAC then separate license is required.

Regards

My question is if i will upgrade the SEPM with 12.1.4, will snac auto upgrade?

No,You need to upgrade SNAC also

are you using Host integrity or do you have DHCP , LAN, Gateway enforcer?

I have DHCP , LAN, Gateway enforce.

You can also upgrade the snac

https://www-secure.symantec.com/connect/forums/snac-client-upgrade

Do you need more help here ?