Hello Premkumar sir,
As minioxidil helps to preserve existing hair and to give strength to the hair or roots available , There is no action of minioxidil on non hairy area or bald area , people see the velus hair post application of minioxidil on bald area , but these hair do not achieve the expected growth they are very thin and fall out once minioxidil is stopped.
The minoxidil lotion when applied topically widens the blood vessels and opens the potassium channels this helps to get more blood supply and oxygen + growth factors to the hair follicles , most of the people see hair loss after application of minioxidil , as miioxidil may cause follicles in the telogen phase to shed off then the new anagen phase replaces it with strong hair.Minioxidil works to prolong the growth phase of hair follicle , it is the FDA approved medication used in both male and female pattren hair fall.
So minioxidil will help you the preserve existing hair - it may not help us as per your expectation in bald area.
Also it will be better to see a good dermatologist near your area and get the consultation done.