First it is important to find the reason for hair fall. It can be due to dandruff, malnutrition, any typhoid like infection, hypothyroidism...... or due to some other reason. If every thing is fine then you may try for any hair root simulator oils. But, if you find 'some other reason' causing hair fall, you have to treat the causative factor first. Even if your tap water doesn't suits you, it causes hair fall.........
Next Steps
Provide more details for better diagnosis and history of any medicine usage.