Conditions for use of 2NT raise in opener's side :

1M    Pass       2NT           = 6-11 HCP, 4 cards support (no 4-3-3-3). At least 9 DH. You can not play 3NT.

 

1M     overcall       2NT     =  6+  HCP, 4+ cards support, too strong for 3M.

1♠           X              2NT     =  9+ HCP, 4+ cards support, too strong  for 3♥ (7-8 HCP) or 3♠ (2-6 HCP)

1♥           X              2NT     =  9+ HCP, 4+ cards support, too strong for 2♠ (7-8 HCP) or 3 ♥ (2-6 HCP)

For developments   1M        2NT

 

But also in overcaller's side :

1x          1M              2NT   = 8+ HCP, 4+ cards support, too strong for 3M(4-7 HCP)

For developments natural continuation.