Hello doc, my husband is suffering from oligozoospermia. He has low sperm count, abnormal morphology. Is it curable through medicine.?

Oligozoospermia. The condition that you describe is not curable. You husband should have a workup which would include hormone testing, lh, fsh, testosterone level, chromosome testing and possible a testicular biopsy.
Meds may help some. See a reproductive endocrinologist if you are trying to conceive, who may also refer your husband to urology. Hormone tests for men with low sperm count: total testosterone, estradiol, lh, fsh, tsh, prolactin. Some need genetic testing. Men with hormone issues may get better sperm counts with Anastrozole (off-label use). Severe sperm problems need ivf with icsi (intracytoplasmic sperm injection).