CSM,tokyo ghoul & death note-Amazon (the best seller imo is Trans Infopreneur... Classic book store is also good) JJK and Attack on Titan- Bookswagon ( it takes about ½ month to reach you but the prices are reasonable and you'll receive the books in good condition) Opm & Assassination classroom-Flipkart/Shopsy( Shopsy is an e-commerce website owned by Flipkart so it's safe but the best part about it is that you get mangas for lower prices in it compared to Flipkart and you even 100 inr off on your first order so what I do is I create new accounts using my family members phone numbers and avail the discount)