I followed the instructions mentioned in this NetBeans Wiki to install NB 6.0 on my ubuntu. But I feel some more information can be added to this wiki. For example, when i ran the command "
sudo apt-get install sun-java6-jdk", ubuntu complained to me that this package is not found in its repositories.
The problem here is that the package sun-java6-jdk is available in the ubuntu "multiverse" repository which is disabled by default. In ubuntu, the repositories are defined in the file "/etc/apt/sources.list". Take a backup of this file, in case if you want. Now open this file and uncomment the lines which define the "universe" and "multiverse" respoitories.