How much space required to install netbackup 7.5.0.5 client on linux

i would say for  7.5.0.5 go with Minimum of 2 GB space for Clients , in future if you need to collect any logs and also apply the upgrades.

for your reference 

below are the values for netbackup 7.6 guide says...

Red Hat Enterprise Linux 5 x86-64 1580MB 
Red Hat Enterprise Linux 6 x86-64 1580MB 

Red Hat Enterprise Linux 4 POWER      466MB
Red Hat Enterprise Linux 5 POWER      466MB

Red Hat Enterprise Linux 5 z/Architecture     1070MB 
Red Hat Enterprise Linux 6 z/Architecture      1070MB

Binary sizes are documented in NetBackup Release Notes 

All NBU 7.6 documentation can be found here:  http://www.symantec.com/docs/DOC6488

Thanks Nagalla & Marianne ,

You both are right but when i marked as solution to marianne post after that i wanted to mark as solution to Nagalla post as well but did not get option to on the Nagalla post :)

But Nagalla Specially Thanks For your Reply