English language fluency is one of the mandatory requirements for a Tier 2 General Visa. You will be awarded 10 points for English Language fluency by successfully showcasing EITHER of the following:
1. Be a resident of majority English-speaking country (Check the list here -
http://www.ukba.homeoffice.gov.uk/pointscalculator). Assuming you will be filing for the visa from India, this option does not apply to you in all probability.
OR
2. Provide evidence of holding a degree which is equivalent to (or higher than) UK Bachelors degree. Please use the points calculator to find out if your degree is approved by NARIC as being equivalent to UK Bachelors degree. Points Calculator is on the top right-hand corner of this page -
http://www.ukba.homeoffice.gov.uk/pointscalculator. As you click through this calculator, and reach the English language requirements page, it will show an option of selecting your course, country, university and so on. If the University/Course you were taught at/in, appears in this list, your qualifications are good to go (Going by your post, I think you've already done this).
You will need to provide the original degree certificate and mark sheets when you apply for the visa. In certain cases however, UKBA may ask you to provide further evidence in form of an attested affidavit from the University confirming the course details and other specifics (Type, Duration, When was the degree awarded etc).
Please note that NARIC is a UK agency which provides expert opinion on your qualifications and their equivalence to UK degree.
OR
3. The third way to secure 10 points is by giving an IELTS Exam in India (or English language test). Assuming you are applying from India, you can appear for an IELTS exam through one of the two designated organizations - British Council OR IDP India. Exams are held usually on a weekend at an exam center. You need to book for an exam online. Slots are usually booked in advance and may be available for a date which is probably 6 weeks from today.
Once you appear for the exam, the physical certificate is sent by post to your address. You can check your score online after 11 days of sitting for the exam. When applying for your visa, you will need to provide your IELTS reference number, name and passport number in the entry clearance application. You are NOT required to send the physical certificate to UKBA (Earlier, It was mandatory to send the Physical original certificate along with the visa application however UKBA has changed this rule in the recent past).
You need to score a minimum band score of 4 out of 9 for each aspect of the test (Listening, Reading, Writing & Verbal). If you have a good grasp on the language, you do not need to study for the exam (This is just my personal opinion. I did not study and only prepared by taking 2 sample tests online and scored an average of 8.5 out of 9). As I have mentioned, it will be helpful to get acclimatised with the format of the IELTS exam. There are several test samples available online for free.
Considering your circumstances, Option 2 maybe the best fit for you. If I were you, I would get my degree certificate attested, get hold of an affidavit issued by the University, and provide it along with the application.
Hope this information helps you.
Cheers.