How much time (approximate) do I have to study French to get to the level in which I can be able to live/study in France?

Depends on your personality and temperament in learning new things. It also depends how easy you find French to learn. I find French easy to learn, but it took me 3 years of school study in the UK to get to a reasonably conversational level. Since you have 2.5 years of time before you relocate there, you have that timeframe of practical need to learn it, so I think you'll be fine, all things being equal.

Go. Live in France. You'll learn more in a week than you'll learn in a year of study. I speak from experience with Portuguese. I studied and then lived in Brasil for two years. I've been studying French for years (albeit on my own for the most part) know how to read (Les Miserables, Les Aventures d'Alice au pays des merveilles) know the grammar, know the literature, know the country and culture. I've been there twice and was confronted twice by the basics of casual conversation and pronunciation. It's all about immersion. I am also at that point with Italian and Spanish.

It takes about four years to become totally fluent in a language. But I wouldn't wait that long. Study for a couple months and go get immersed in it. Attitude makes a big difference in your learning; if you are eager, it will come faster and easier.

It solely depends on your capability, a language isn't like mathematics that you learn the rules and apply them. If you are from a country speaking latin languages, it should be fairly easy for you. But the easiest way is to arrive in France, and interact with people in french on an everyday basis. It might do wonders to your french, before you even realise, you'll be speaking effortlessly, expressiing yourself in the french way. Before arriving in France, to make your task easier, try and achieve atleast A2 level. It should be easier for you to grasp the intricacies of the language, when it hits you like a storm. Once you get to know the basic rules of grammer, which honestly don't need learning for hours (you learn them through using), practice polishes your skills. Best of luck.

I was born in the UK and moved to France when I was 10. I have lived here ever since and travel frequently to the UK. I am also a software engineer. Learning a language is an on going process. You couldn't tell if I was French or English when I speak and yet I learn new words every day in both languages. So I wouldn't worry too much about how good your French is. You already speak two languages so you've done the hardest part. Even if your French is poor you would still be able to live and study in France for the following reasons. Programming languages are entirely in English no matter where you work. It's like no other field, where you would have to relearn the vocabulary of your trade. Software engineers' English is usually very good in France. I have even come across entire programming documentation in english (only french programmers/developers). So you would have no problem communicating with other students/colleagues. Although not as good as the Dutch or Germans, the average French person understands quite a lot of English. You would be able to get around and be understood only by speaking English and using gestures. There are large communities of English speaking people in France. If you are ever in need, just head over to the closest English/Scottish/Irish/Australien pub (there are many). As Kelly Amott said you could spend months learning French and still not learn as much as you could in a few weeks in France. When I came to France I could only speak a handful of words in French. But I still managed to make friends and understand the subjects in class after a couple of weeks (I was younger which does make a difference). So as long you can learn more than half a dozen words in two and half years then you will be in better shape than I was !