You would need to pay stamp duty as well as registration fees, both of which are calculated on the value of your property. Costs vary significantly from one state to the next, with some states even factoring in even the gender of the applicant.
Stamp duty is a percentage of the transaction value. In Delhi, for example, stamp duty is collected at 4% of property value in the case of a woman and 6% in case of a man.
Yes, you would need to be there in person for the property registration. You would also need two witnesses to be present.
The property will be registered that very day, but it could take a week to get all the documents in order.
The registration takes place at the office of the Registrar or Sub-Registrar.