SG0002673: IRIX 6.2 Networking Kernel Rollup #6
SG0003289: XFS rollup #14 for 6.2
SG0003490: Irix 6.2 libc rollup + Y2K fixes + MIPS ABI
SG0003566: 6.2 all platform kernel rollup
If you install SG0002673 you might also want to install
SG0003055: Irix 6.2 tcsh and cpio fixes
SG0001404: Irix 6.2 Posix 1003.1b man pages
SG0001645: IRIX 6.2 & 6.3 POSIX header file updates
SG0002000: Irix 6.2 Posix 1003.1b support modules
SG0003356: Pthread library fixes
SG0003458: rld rollup #15
All the patches should be available with a free Supportfolio account from SGI.
For some of these patches there are later revisions still but they are not free.
In some cases you can get away with using an earlier revision of a patch ie. instead of 3356 you might be able to do with 2420.
There are many other patches that you might want to install but I won't list them all here. Just get all the free patches for Irix 6.2 from supportfolio and install them if possible.