Replace nth to end of line with sed

[rob31312]

How can I replace the 6th dot to the end of the line?
I'm using sed 's/\.//6' but that only deletes the 6th dot. I want to delete the 6th, 7th, 8th, to the end. I tried using sed 's/\.//6g' but I get an error.

 

[danielhozac]

Something like [tt]sed 's/\..*//6'[/tt] perhaps? //Daniel

 

[iribach]

post an exemple!
assumed you have:
a.b.c.d.e.f.x.y.z
s/\(.*\.\)\(.*\.\)\(.*\.\)\(.*\.\)\(.*\.\)\(.*\.\).*/\1\2\3\4\5\6/g
gives you:
a.b.c.d.e.f.
try also cut
cut -d\. -f1-6