UK

Along with the essential course completion requirements, your application for the Graduate Visa in UK depends on the following aspects of your course as well:

1. the university or your course provider
2. how long did you study in the UK
3. what kind of a course you studied - bachelor's, master's or any doctoral course

No, studying on a Graduate Visa in UK is generally not possible. Students can do so only if their chosen course is not eligible for a student visa in the UK. If you choose a course that is eligible for a student visa then you can apply for the extension of your UK student visa instead. The courses allowed on a Grdauate visa may include professional, recreational or online courses like short courses or skills development that are not covered by a full Student visa. 

UK's Skilled Worker Visa's fee is not refunded upon its grant and usage. The Skilled Worker Visa in the UK is granted for a minimum of 3 years once you start using it, its fee along with the IHS fee become non-refundable.
However, if you work in healthcare roles, then, you might get an automatic IHS refund for working about 6+ months or if your visa was shorter than applied for. 

Since applicants need to pay for a minimum of three years when applying for a Skilled Worker Visa in the UK, applicants with a job offer with lesser in length than that keep looking for a UK work visa that's valid for only 2 years. 

For that reason, one can apply for a "India Young Professionals Scheme visa". This visa allows Indians from 18 to 30 years old to work in the UK for 2 years. The only conditions for getting this visa include- 

• you must have a minimum saving of £2,530
• you must get selected in the India Young Professionals Scheme ballot 

For UG students, a BSc (Hons) in Computer Science from the Uni of Greenwich would cost INR 22 Lakhs for full-time students. Part-time students can pursue the same for INR 11.65 Lakhs. An MSc in Computer Science takes around INR 22.85 Lakhs for full-time students. A part-time Master's would cost INR 13.85 Lakhs.

UK PR also called Indefinite Leave to Remain usually takes 5 years if you're on a work visa like the Skilled Worker Visa. However some family visas (like being married to a UK citizen) or long-term residence may allow you to apply sooner, around 2 years.

For getting UK Skilled Worker visa, you  must have a job that pays a minimum of £41,700 per year or standard salary for that job - whichever is higher. However some jobs have low salary requirements like  healthcare workers, PhDs or workers under 26. These people might get qualified with salaries as low as £25,000.

Students applying from outside the UK need to pay the following UK work visa fee -

• For up to 3 years - £769 per person 
• For longer than 3 years- £1,519 per person 

Students earn 60 ECTS credits for one full year of study in Europe. This makes 30 credits per semester. A 3-year bachelor's comes to 180 credits total. A four-year Bachelor's degree equals 240 credits total.

The answer is - contact your supervisor. Some universities also share the process to getting your PhD funded by the university. You must contact your PhD supervisor for the same, in most cases, a PhD scholarship is awarded at the time of accepting your application. If you don't get a scholarship from your university, you can also apply for an external PhD scholarship in UK. The process to apply for each scholarship is to visit their respective websites and follow the steps as indicated.