I agree with Felicity that a 4-6 week PCT will not be sufficient. I also agree with Ano's advice to taper down.
Assuming you were 'on' for a long period... greater than 1 year, tapering down to a steady, TRT dose and then transitioning into PCT rather than immediately following a blast would be beneficial. I've even seen guys transition even further to a low dose am dbol method to create a morning spike (rather than an elevated level) that more closely resembles their natural levels/rhythm.
As for PCT and your use of Serms:
My ideas differ a little because although I think both Clomid and Nolva should both be used, I think they should be staggered and overlapped. Clomid and Nolva are similar, but of course not the same. Although they both bind to estrogen receptors, they don't bind identically to all of the same receptors, which is the reason to use both. Its the same principal behind a proper cycle, you don't want to use two identical steroids that essential compete or at the very least, add no additional benefit. But Clomid and Nolva can also compete for some of the same receptors. This is why (IMO) a lot of guys dropped the 2 Serm protocol years ago...they found Clomid to be nearly as effective as the combo. Therefore, a lot of forum bro science out there says 2 Serms are unnecessary.
Because Clomid has been shown to be superior for restart purposes, its my strong opinion that Clomid is best used by itself when starting PCT. Then, midway through PCT, introduce Nolva. I've personally tried this a number of different ways: Clomid and Nolva both for 4 weeks, Clomid only, Nolva only, No Serms at all, and I've also tried this method of staggering and overlapping the two which I feel is significantly more effective. You'll notice the physical effects of the restart about 4-8 days after starting Clomid. But then you'll also notice a 2nd boost midway through PCT when you start Nolva. Essentially, it allows your PCT to be progressive (like a cycle).
This method also has benefit because it allows you to run a long PCT or Restart without running Clomid the whole time. Although Clomid is more beneficial for restart purposes (also prescribed by more TRT doctors), it's also usually ran at higher doses (compared to Nolva) and it can also yield more estrogen like side effects. Nolva on the other hand tends to be more tolerable and can be tolerated for longer periods.
Good Luck
One more note: always taper your Serms