First, i want to tell that I don't have any experience with MPLS or EoIP yet . BUT i am looking for the possibility of both technology, so i will ahead to that one without looking around .

please take a look at the below diagram:
1. Each customer will have one VLAN (ex. VLAN100).
2. In order to get redundancy, OSPF will be used inside the backbone connecting R1,R2 and R3.
3. Point-to-Point IP will be provided to each customer. one IP will be on customer router and other IP will be on the Gateway Router.
4. MPLS or EoIP will be use to make the backbone transparency. Is it possible??

Note: BTS will act like trunk port connecting back to the gateway router.

Is it possible or not?

The short answer is - yes, it is possible, using either technology. And probably in some other ways as well, e.g. simply by using bridging.