Yes, you can directly jump from AIX 7100-01-06-1241 to AIX 7100-02-03-1334
Just make sure you select the prerequisites (check mark), while downloading TL02SP03 .
You don't have to do a 2 step process, Directly you can jump to your desired level.
But, make sure you have a copy of your previous OS (either multibos or alt_disk ).