Hi Andrii,
You don't say exactly how many snapshots you have, but there are definitely limitations. Below is a link to the Veritas NetBackup for VMware Administrator's Guide (8.0). Have a read from the last paragraph on page 29:
https://www.veritas.com/content/support/en_US/doc/ka6j00000000AFeAAM
A number of the limitations are from VMware, as you can see in their best practice KB article: https://kb.vmware.com/s/article/1025279
VMware also doesn't recommend maintaining snapshots on a regular basis, as per this statement:
Snapshots can negatively affect the performance of a virtual machine. Performance degradation is based on how long the snapshot or snapshot tree is in place, the depth of the tree, and how much the virtual machine and its guest operating system have changed from the time you took the snapshot. Also, you might see a delay in the amount of time it takes the virtual machine to power-on. Do not run production virtual machines from snapshots on a permanent basis.
I would definitely be trying to clean this up ASAP and removing the snapshots. As to wether it will backup successfully, the only way to know is to try, unless of course you have already passed the limits shown in the docs above, in which case it should fail.
I'm guessing you haven't done a NetBackup VMware backup on this before. One thing to note is that if you do, you will get one more snapshot - NetBackup tells VMware to take a snapshot, NetBackup backs that up and when finished tells VMware to delete the snapshot. Depending how close you are to VMware limits, that could cause the backup to fail (although the snapshot requested by NetBackup should be deleted at the end).
Do you have a NetBackup agent installed in this VM? If so, you could do a traditional agent based backup at least so you have some recovery point to go back to. As a matter of urgency I would look at cleaning up those snapshots ASAP.
Hope this helps,
Steve