In this paper,we study double circulant codes of length 2n over the non-chain ring R =Fq + vFq + v2Fq,where q is an odd prime power and v3 =v.Exact enumerations of self-dual and LCD double circulant codes of length 2n over R are derived.When n is an odd prime,using random coding,we obtain families of asymptotically good self-dual and LCD codes of length 6n over Fq.