Bachelors

It is a bachelors course with 3 years duration. Check out the link below for more details:
https://www.shiksha.com/design/communication-design/course/b-sc-in-game-designing-and-development-iifa-multimedia-srinivasanagar-bangalore-251170

Of course, you can get admission via lateral entry and Admission is based on the marks obtained in Diploma/ B.Sc.
Check out the detail below:
https://www.shiksha.com/b-tech/course/b-e-lateral-entry-anjuman-college-of-engineering-and-technology-nagpur-238780

You do have specialised courses in civil as Geo technical, construction management, structural engineering and so on. Because of the specialisation, you become more employable. You also save one year of your life as it is 3 years programme in UK.

Yes, you can get it. However only the course director can take decision as they have to check weather you have covered all necessary topics in your course. You need IELTS or PTE to prove your English proficiency.

Hello Rakesh,
Lateral admission or admission directly into second year of engineering after completion of Diploma is a very typical Indian phenomena. When you are thinking of studying abroad, I am afraid, lateral admissions are just not available but your Diploma studies will come in handy for getting you admission for an engineering course. Perhaps exactly on the same lines what IITs do in India.
Best wishes to you.

Hi Friend, according to me maths is not compulsory in class 12th. If you are interested in maths then opt it or if you are not interested then go through biology but you should be clear in your opinion that after 12th you are going through medical field and if you are not clear then you can opt maths as a optional subject with biology as I did in class 12th if you don't want then go through biology but keep in mind that you should do your best.

You have to do class 11th and class 12th schooling from outside India and appear for SAT exam.

The problem with UK is the stay back period is very low, i.e., only 4 months. So, basically you only have 4 months to find a job after your graduation, which is not at all easy as when companies notice that you only have 4 months of stay back, most of them reject your application because they want candidates who have sufficient amount of time to stay back in UK. Of course, finding the job is not impossible, but it is really very hard. Once you find a job then automatically, you will get work visa and then you can apply for PR. Also, the companies won't come to you there like in India. You have to go behind them for a job. All the best.