Hi, i wanted to check if we will be able to use the squirrel code of imp003 for imp006 version, or do we need to make a lot of changes
It depends a lot on your squirrel application.
The first thing I would review are the hardware peripherals you use in your squirrel code. imp006 has more peripheral pins available but some functions have moved to different pins, and a small number of imp003 features are removed or reduced (e.g. sampler, 4 pin uarts, nv table).
imp006 has a slower clock than imp003 so runs code ~28% slower, but otherwise consumes less power, has double the code space and almost double the available RAM.