Required Documents for Bachelors/Masters:
1) Matric/O Levels Mark sheet / Certificate
2) Intermediate/A Levels Mark sheet / Certificate
3) Bachelor Transcript / Degree (if applying for Masters Degree)
4) Valid Passport
5) Updated CV
6) Experience Letters
7) SOP (Statement of Purpose)
8) Any UKVI Approved English Test
If all the above mentioned documents are completed then the offer normally took a week to process.