what is difference between both or both are the same?
How can we configure the Static SLP in cisco router network?
I guess that you are talking about MPLS VPN case, where you have 2 labels, the Top label, which is the LDP label (and it is the label to reach the egress PE router), and the VPN label which is propagated via MP-BGP between the PEs and they are used to reach the VPN customer interfaces.
And yes you can overlap VPNs using multiple RTs.
I would suggest another book beside Swaroop's suggested one.
Luc De Ghein, CCIE
 Swaroop, i guess we were writing nearly the same answer at the same time :)
There are 2 labels in a MPLS VPN scenario. If its only MPLS there is only 1 label.
Now coming to this, the first required label is called MPLS IGP label, as this label is assigned using LDP based upon IGP path (OSPF,EIGRP,STATIC).
Now you have labels to switch across the MPLS core (MPLS IGP label), but the core doesnt know anything about the connected customer VPN's or their routes, so MPBGP comes into picture. MPBGP uses route targets to exchange routing information from different PE's and builds the VRF routing table and then assigns labels to those routes.(but since the BGP session was established between the PE's using the existing MPLS IGP labels, we need to use 2 labels when sending traffic to the other end of the VPN;s. (1) MPLS IGP Label (2) BGP VPN Label.
And yes using multiple RT you can have connecitivty with multiple VPN;s, this is called as Extranet.
As mentioned in the previous post, the books would be very helpful too.
# As I said Mohammed , it happens all the time, when we are active at the posts.