Substituted bicyclic compounds of formula (I), their tautomers, polymorphs, stereoisomers, prodrugs, solvates, hydrates, N-oxides, co-crystals, pharmaceutically acceptable salts and pharmaceutical compositions containing them are disclosed, as well as processes for preparing and using the compounds. These compounds are useful in the treatment, prevention, prophylaxis, management, or adjunct treatment of all medical conditions related to inhibition of retinoic acid-related orphan receptor gamma (RORy). Representative conditions include inflammatory and/or autoimmune disorder, rheumatoid arthritis, psoriasis, psoriatic arthritis, multiple sclerosis, inflammatory bowel disease, allergic diseases, asthma, COPD, cancer, cell proliferation, type 1 diabetes, myasthenia gravis, hematopoetic disfunction, systemic lupus, crythematosus or other disorders.