Thanks for the comments. Yesterday I again took him to the vet doctor. He gave the same medicine (yellow color medicine, I don't know the name) for Deworming. Yesterday we put the first vaccination and the doctor mentioned some oinment for that skin problem. I have started using it from today.
Thanks for the advices. So, to summarize I need to avoid, Dettol and use Salvon , avoid Milk with Idli and need to check on alternate foods for him. Since he is put with vacinnation yesterday only, I am planning to start with Nemocid a week after with the dosage as advised by Anil. Will post you on how it progress. I have posted some pic of him (we have named him 'Billa') in my profile. Do check it when u find time.