You must apply at least 3 months before your intended travel date and the earliest you can apply is 6 months before your course starts.
A student visa in the UK, allows you to stay there for the duration of your course. You can stay up to a total of 2 years for below degree level courses and for a total of 5 years for degree level courses or higher.
You would be required to pay a fee of £490 (approximately ₹51,700). Additionally, the Immigration Healthcare Surcharge is also payable as a part of your application.