bidding stayman then bidding 4minor shows a 4M/6m hand with no major-suit fit. If you only have a 6m hand, try 3S first. Most play that as minor-suit-stayman (MSS). If pard bids 3N, then bid 4m to show your slammish long minor hand. If pard bids 4D when you have clubs, just bid 6C.

 

With a good 6card minor, I would suggest you bid 6minor rather than 6N. At IMPS, slam bonus is far more important than the few extra points NT provides. Most hands will play the same, but some hands will provide more tricks at a suit than NT.

 

Sometimes it is best to just jump to 6m over 2N to prevent confusion.