Bhai idhar kya random logon ki advice le raha hai. Go consult a dermat, they will work with you to find a suitable shampoo
If you're in Bangalore, stop washing head with tap water. Use water can/drinking water basically
Never wash head even with warm water. Hot water is absolute no no.
Excess oil leads to dandruff, avoid oiling overnight
If at all you feel the need to, leave oil for 30 mins only and then wash
If you wear a helmet often while on 2W use a cloth/handkerchief between head and helmet
Use an anti dandruff shampoo 2 times a week. Apply on wet hair and leave for 10-15 mins (yes you read that right). After 10-15 mins, go for a bath. Use a shower cap for those 10-15 mins to avoid dripping
Shampoo examples - head and shoulders, any shampoo with zinc pyrithione and ketoconazole
All of this is doctor advice, tried and tested by myself
Some of these will help counter/prevent hairfall issues as well to some extent
Ketoconazole shampoo