The c6300 is a cable modem/router. You have posted your message in the section of this community given over to Apps and Services. (This is easily done, given Netgear's impenetrable community structure.)
You might get better replies, and find other answers, over in the appropriate section:
Cable Modems & Routers
Which Internet service provider is this?
It might help if you unravelled this bit:
@Mikk3201 wrote:
it wast working good just in a second it restarted and didn’t connected to internet anymore
Does that mean it was working good for a second? Did it spontaneously restart itself?
What to do the LEDs on the C6300 look like?
There is a support for the C6300, including a manual, somewhere at the end of this link:
>>>> C6300 | Product | Support | NETGEAR <<<<
