Hi. Can I use 2 fiverr accounts on same system in different browsers
No one is allowed to have two accounts, even if they use different browsers.
Also, if you mean, you have a second user who wants to set up a Fiverr account and use the same system, that is only allowed if you get permission from CS and you and your friend that is sharing your system do not offer the same service. Otherwise, both of the accounts using the same system could be taken down by Fiverr.