Rip Load Balancing : 

In above topology :

Configure Rip on all Four Routers : 

R1(config)#router rip
R1(config-router)#version 2
R1(config-router)#no auto-summary

R1(config-router)#network 13.0.0.0  
R1(config-router)#network 14.0.0.0
R1(config-router)#exit

R3(config)#router rip
R3(config-router)#version 2
R3(config-router)#no auto-summary
R3(config-router)#network 13.0.0.0
R3(config-router)#network 23.0.0.0
R3(config-router)#exit

R4(config)#router rip
R4(config-router)#version 2
R4(config-router)#no auto-summary
R4(config-router)#network 14.0.0.0
R4(config-router)#network 24.0.0.0
R4(config-router)#exit

R2(config)#router rip
R2(config-router)#version 2
R2(config-router)#no auto-summary
R2(config-router)#network 2.0.0.0

R2(config-router)#network 23.0.0.0
R2(config-router)#network 24.0.0.0
R2(config-router)#exit

now look at Routing Table at R1 : R1 is getting route of 2.2.2.2/32 via 2 paths one via 13.0.0.3 and other via 14.0.0.4 with same metric 2

command :

R1#show ip route rip 
Codes: L - local, C - connected, S - static, R - RIP, M - mobile, B - BGP
       D - EIGRP, EX - EIGRP external, O - OSPF, IA - OSPF inter area 
       N1 - OSPF NSSA external type 1, N2 - OSPF NSSA external type 2
       E1 - OSPF external type 1, E2 - OSPF external type 2
       i - IS-IS, su - IS-IS summary, L1 - IS-IS level-1, L2 - IS-IS level-2
       ia - IS-IS inter area, * - candidate default, U - per-user static route
       o - ODR, P - periodic downloaded static route, H - NHRP, l - LISP
       + - replicated route, % - next hop override

Gateway of last resort is not set

      2.0.0.0/32 is subnetted, 1 subnets
R        2.2.2.2 [120/2] via 14.0.0.4, 00:00:02, FastEthernet1/1
                 [120/2] via 13.0.0.3, 00:00:13, FastEthernet0/0
R     23.0.0.0/8 [120/1] via 13.0.0.3, 00:00:13, FastEthernet0/0
R     24.0.0.0/8 [120/1] via 14.0.0.4, 00:00:02, FastEthernet1/1

So now Rip has installed both paths into routing table . Now which path will be used depends upon forwarding mechanism used .By default forwarding mechanism used is CEF ( Cisco Forwarding Mechanism ) so it will do per-destination network based load - sharing.