It really depends on what you mean by "pick up". If you mean you want to strum simple chords or do some basic fingerstyle, then sure, you can easily do it in 3-6 months with enough practice. You did not mention what type of guitar you intended to learn....steel-string/classical/electric? I would definitely recommend an acoustic steel-string, as it is the most versatile.
You can learn on your own, but it would be best if you had a friend to show you the basics. It will be a little easier if you already have prior musical training in another instrument such as the piano. If you can afford it, find a good guitar teacher and take lessons for a few months. Once you have all the basics in place, I suggest that you stop the lessons and start learning songs by ear. YouTube is once of the best (and cheapest!) ways to learn the guitar. I've been playing for 15 years and only had one teacher while I was in school. I learned for about 1 year, then realized that there really wasn't anything he was teaching me that I couldn't teach myself. So I've been learning from books, CDs, MP3s and Youtube ever since. It's tough sometimes, but that's what makes it satisfying when you finally nail a piece you've been learning for months 
I strongly advice *against* buying a RM100 guitar. You might think it's worth it in the beginning, but after you've improved and played better guitars, you won't ever want to touch it again. Then that would be RM100 wasted. Many guitarists think that the price of the guitar you buy depends on how good you are. I don't think this is a very good approach. When people ask me: Am I good enough to deserve an expensive guitar? I say: How good a player do you *want* to be? What many people don't consider is that a good guitar sounds *and* feels better. As a result, you will want to play and experiment with it more often. This makes you a better player! 

So, I always recommend that, *if* you are quite serious about playing the guitar, buy an instrument that is *the best you can afford*. If you do not have a lot of $$$, a Yamaha acoustic is a good place to start. Their entry-level guitars are about RM280. Their more expensive ones are better than many Taylors, Takamines and Seagulls.