This is actually a lot easier than waiting until Admin tech 10.
Basic guide is start as Sirhand. In first few months you'll jump into a "reclaim land from Dehli" war (as well as be granted independence). You can full annex them and then form Dehli as yourself. Then you can continue conquesting, doing whatever you need to do since you already have the provinces to form Punjab.
Pick religious as your first idea group and work towards the missionary strength. You can ignore tech for the rest of it so don't be afraid to fall behind (unless you plan on playing after getting the achievement).
Once Sikhism spawns, convert to Sikhism and convert the Punjabi provinces. Then, release Punjab as a vassal and play as them. Boom you are a Sikh Punjab.