If there is no 64bit avast linux version then can you install the 32bit version on ubuntu 14.04 64bit? Thanks.
There is a 64b version of avast for linux - see https://forum.avast.com/index.php?topic=145973.0
If you mean a “free” linux version of avast, then there is no such version at all (except the obsolete and
unsupported “version 4” based one).
Thank you.