The present invention relates to fused heterocyclic compound of Formula (I), a stereoisomer, a tautomer, a pharmaceutically acceptable salt, a pharmaceutically acceptable solvate, a prodrug, a polymorph, N-oxide, S-oxide, or a carboxylic acid isostere thereof; processes for their preparation; pharmaceutical compositions comprising said compounds; and their use for the treatment of the diseases or disorders mediated by GPR120 receptor.