Through the picture it seems you have tinea cruris, which is a fungal infection.
It is treatable with medications.
Do you have any other issue, for which you are taking any medication, as the oral medication which we give may react with other medications if you are taking.
You can let me know about this, then I can prescribe you the medicines.
Health Tips
avoid sweating, maintain hygiene, do not use any home remedy or steroid creams or anything which might irritate your skin further