Hello. English is not my native lang, so sorry ;) but i hope u will understand.
1) I'm looking for a remote desktop to use it threw Tor. I mean that when i connect to a dedicated server my own Ip wouldn't be compromised.
Does it looks like this? My PC (RDP Client) -> Node 1 -> ... -> Node N -> Dedicated server (RDP Server)
or it will connect directly? My PC (RDP Client) -> Dedicated server (RDP Server) so my IP will be compromised?
2) I can't find RDP client in Talis.
When i'm trying to install: "sudo apt-get install remmina remmina-plugin-rdp"
i get:
Reading package lists... Done
Building dependency tree
Reading state information... Done
E: Unable to locate package remmina
E: Unable to locate package remmina-plugin-rdp

Tails ensure that they will be no direct connections through the Internet between Tails and the server you are connecting to.
Remmina should use GNOME SOCKS proxy settings, so no extra configuration should be required.
You were nearly there. Please try:
(Content of Debian repositories needs to be refreshed on each boot.)
Please write some feedback if it works fine.