The List
There are 467 6 letter words with N as the first letter. The highest scoring is NUZZLE at 24 points in Scrabble. 1 of them contain no vowel at all: NYMPHS.
NABBEDNABBERNABLASNABOBSNACHASNACHESNACHOSNACKETNACREDNACRESNADIRSNADORSNAEVESNAEVUSNAFFEDNAFFERNAFFLYNAGANANAGARINAGGEDNAGGERNAGORSNAHALSNAIADSNAIANTNAIFERNAIFLYNAILEDNAILERNAIRASNAIRUSNAIVERNAIVESNAKERSNAKFASNALEDSNALLAHNALLASNAMELYNAMERSNAMINGNANCESNANDINNANDOONANDUSNANISMNANITENANKINNANNASNANNIENANOBENANOOKNANUASNAOSESNAPALMNAPERYNAPINGNAPKINNAPOOSNAPPASNAPPEDNAPPERNAPPESNAPPIENAPRONNARCOSNARDEDNARDOONARIALNARINENARKEDNARRASNARROWNARWALNASALSNASARDNASHISNASIALNASIONNASTICNASUTENATANTNATIONNATIVENATRONNATTERNATURANATURENAUGHTNAUNTSNAUSEANAUTCHNAUTICNAVAIDNAVARSNAVELSNAVEWSNAVIESNAWABSNAYSAYNAZIRSNEAFESNEAFFENEALEDNEANICNEAPEDNEARBYNEAREDNEARERNEARLYNEATENNEATERNEATLYNEBBEDNEBBUKNEBECKNEBEKSNEBELSNEBISHNEBRISNEBULANEBULENEBULYNECKEDNECKERNECTARNEEDEDNEEDERNEEDLENEEDLYNEELDSNEELESNEEMBSNEESEDNEESESNEEZEDNEEZESNEFASTNEGATENEIGHSNEINEINEIVESNEKTONNELIESNELLIENELSONNEMNEDNEOCONNEONEDNEPERSNEPETANEPHEWNEPITSNERALSNERDICNEREIDNEREISNERINENERITENERKASNEROLINEROLSNERVALNERVEDNERVERNERVESNESHERNESSESNESTEDNESTERNESTLENESTORNETFULNETHERNETOPSNETTEDNETTERNETTIENETTLENETTLYNEUMESNEUMICNEURALNEURONNEUTERNEVELSNEVOIDNEWBIENEWELLNEWELSNEWESTNEWIESNEWINGNEWISHNEWSEDNEWSESNEWSIENEWTONNEXTLYNGAIOSNGANASNGATISNGOMASNHANDUNIACINNIBBEDNIBBLENICADSNICELYNICESTNICETYNICHEDNICHERNICHESNICHTSNICISHNICKARNICKEDNICKELNICKERNICKLENICKUMNICOLSNIDATENIDGETNIDIFYNIDINGNIDORSNIECESNIELLINIELLONIEVESNIFFEDNIFFERNIGERSNIGGLENIGGLYNIGHEDNIGHERNIGHLYNIGHTSNIGHTYNIGIRINIHILSNIKABSNIKAHSNIKAUSNILGAINILGAUNILLEDNIMBEDNIMBLENIMBLYNIMBUSNIMMEDNIMMERNIMRODNINCOMNINCUMNINETYNINJASNINONSNINTHSNIOBICNIPPEDNIPPERNIPTERNIQABSNIRLEDNIRLIENIRLITNISEISNISGULNISHESNISSESNITERSNITERYNITHERNITONSNITRESNITRICNITRIDNITRILNITROSNITROXNITRYLNITWITNIXERSNIXIESNIXINGNIZAMSNKOSISNOBBLENOBBUTNOBLERNOBLESNOBODYNOCAKENOCENTNOCHELNOCKEDNOCKETNOCTUANODDEDNODDERNODDLENODOSENODOUSNODULENOESESNOESISNOETICNOGAKUNOGGEDNOGGINNOINTSNOISEDNOISESNOMADENOMADSNOMADYNOMINANOMISMNONAGENONANENONARTNONARYNONCESNONCOMNONEGONONETSNONFANNONFATNONGAYNONMANNONMENNONPARNONTAXNONUSENONWARNONYLSNOODGENOODLENOOGIENOOKIENOONEDNOONERNOOSEDNOOSERNOOSESNOPALSNORDICNORIASNORITENORMALNORMANNORMASNORMEDNORSELNORTHSNOSEANNOSERSNOSEYSNOSHEDNOSHERNOSHESNOSIERNOSIESNOSILYNOSINGNOSODENOSTOCNOSTOINOSTOSNOSTRONOTARYNOTATENOTCHYNOTERSNOTHERNOTICENOTIFYNOTINGNOTIONNOTOURNOUGATNOUGHTNOULDENOULESNOUNALNOUSESNOUSLENOVATENOVELSNOVENANOVICENOVITYNOVUMSNOWAYSNOWISENOYADENOYAUSNOYINGNOYOUSNOZZERNOZZLENUANCENUBBEDNUBBINNUBBLENUBBLYNUBIASNUBILENUBUCKNUCHAENUCHALNUCLEINUCULENUDELYNUDESTNUDGEDNUDGERNUDGESNUDNIKNUFFINNUGGARNUGGETNUKINGNULLAHNULLASNULLEDNUMBATNUMBEDNUMBERNUMBLYNUMDAHNUMINANUMNAHNUMPTYNUNCIONUNCLENURDLENURHAGNURLEDNURSEDNURSERNURSESNURSLENUTANTNUTATENUTJOBNUTLETNUTMEGNUTRIANUTTEDNUTTERNUZZERNUZZLENYAFFSNYALASNYANZANYASESNYBBLENYLONSNYMPHANYMPHSNYSSAS