About Netbackup upbrade

Hello,

We have Netbackup 7.1 and it's been about three or four years they didn't buy support contracts or new versions of Netbackup. Now, it is necessary that they acquire the new version of Netbackup 7.6.

I would like to know if we should buy support contracts or the new version licences to have it, and if there will be some cautions to pay because we didn't pay previous years of contracts.

Thanks in advance, and regards