This can be done by many methods, but prefer to use “show run | i router|redist” to see if there is any redistribution currently on the device. Since all routing processes include the term “router” and all redistributions include…well “redistribution”, this command will show you which – if any – redistributions are currently configured on a device:
Rack1R6(config)#do sh run | i router|redist
router eigrp 10
router ospf 100
router-id 150.1.6.6
redistribute connected subnets route-map CONN->OSPF
In this case we can see that we are redistributing connected routes into OSPF using a route-map. Good to know before beginning mutual redistribution.
Rack1R5#sh run | i router|redist
router eigrp 100
router ospf 100
router-id 150.1.5.5
In this case we can see that there is no redistribution currently occurring on this device.
I run through this check any time I am about to configure redistribution. I also note any redistributions on my lab topography, but it’s always good to “measure twice, cut once” 
