Krnage :
I have a 460W, I just watch on Dell
If the Dell PSU has a 6-pin connector and you get a 1060 that only requires a single 6-pin, you are fine as-is. If you decide to get one of the factory overclocked 1060s, then you'll want to upgrade to a
quality 500W or better.
Your PSU may actually be a 460W unit. Check the nameplate on it and see if this is it:
https://www.techpowerup.com/forums/attachments/sam_0856-jpg.69666/