Short term

There are various short term Diploma or Certificate course to make a bright career in aviation field. Different course is needed in aviation field, because there are various type of work in this field and by doing one single course it is not possible and it is also not possible to merge all the course into one course, as syllabus is very large which is not possible to learn by one student. That's why different course has been designed by IATA such as Ramp planner, air navigation services, cargo manager, Managing the travel and tourism and various other course. Yes, it has a great impact on student CV and job opportunities get rise after doing these Certification or Diploma course. These course are designed and certified by IATA, so these certificate have really a good value in market. Student can get better job and facilities by doing these course.
For complete details about the course certified by IATA visit the link provided
http://www.iata.org/training/diploma_program/Pages/index.aspx

If you have interest in game development, then you can sure give a shot and go for it once you complete java course. But, it is not really used in game designing.
Technical reasons:
- Most of the best 3D game engines are written in C/C++. This is a big deal since most game developers don't want to compromise on their 3D engine, but nor do they want to write one from scratch. Java has jMonkeyEngine which is open source and actually really good but it still can't yet compete with the Unreal Engine.
- For some very rare situation, there are advantages in getting "close to the metal" in C or assembly language, specifically for access to special hardware features. This is not so important nowadays, but professional game developers still like to have the option.
- Java has a garbage collected, managed runtime. 99% of the time this is a huge advantage, it certainly makes coding easier and less error-prone and is one of the big reasons why Java is so popular. However, it does cause an occasional latency issue for games as garbage collection cycles can cause noticeable pauses. This is getting to be less of an issue with the newer low-latency JVMs but is still an issue for graphically intensive games where maintaining high FPS is critical.

1. Web Designing –
Web designing is a great opportunity for those who want to work independently. Web designing courses deal with various elements of making and maintaining a site. It consists of learning coding languages like HTML, PHP, JavaScript, etc. There are many private institutes that offer such course. One of the notable institutes is Arena group of institutes.
2. VFX and Animation
These courses deal with topics like visual effects, animation, 3D technology, graphics etc. Earlier, this course had few takers. But with the increased demand for VFX and Animation professionals, this course has become popular once again. Again, there are a number of good quality private institutes that offer animation course. One of the best among them is Arena Multimedia. The fees vary from institute to institute.
3. Hardware and Networking courses
Many Indian students are well aware of these courses. Their advertisement keeps appearing on Newspaper and TV every now and then. As they promise, these courses guarantee jobs. When it comes to computer hardware and networking, the most popular institute is Jetking. They have a good placement record. They offer a variety of courses- long and short term. Bright students may also avail scholarships at Jetking.

Hi,
Bollywood music industry is totally a different platform which is based on your talent, luck and network. To become a playback singer, you don't need or require to have a degree or Diploma.
So, I would suggest you to search and pick an esteemed music guru who can groom your talent. Do riyaz and practice regularly. Prepare your demos of latest trends which can present your talent and quality of singing.
Watch singing shows on tv and attend the singing shows, events. Share your audios and videos when asked on TV shows. Try and participate in singing shows. They are the best platforms for you from where you may get chances to enter in Bollywood.
There is no such short-term course that can help your purpose.
if you can afford it, it will be great if you join AR Rahman Music Academy or Suresh Wadkar School of Music.
Hope it helped you.