Yes, it is possible to gain almost 2 inches in less than a year, but as we said, it depends from person to person. Someone might gain 2 inches in 4 months. Someone else might gain 2 inches in 4 years. It's a marathon, not a sprint.
If the other questions are 'Is it possible to gain fast lengths without jelqing? I mean by just doing stretches towards different directions for maybe 20-30 minutes every day?'. Then, yes it is and, I'm not sure. Jelqing isn't going to be the single exercise that grants you inches and inches of length. It will help a bit, but if your other P.E. work is good, leaving out jelqing shouldn't hinder you too much. I try to stretch for about 35 minutes every day. I sometimes stretch for up to an hour. for about 20 days I stretched for an hour a day and I gained 0.2 of an inch in my bone-pressed flaccid stretch length. Make of that what you will.
P.E. is not only about dedication and how good your workout is, but how much time you have to put into it. I've had months where I've been on holiday and I've done huge amounts of P.E. and seen huge gains. Other months I've had no time and could barely manage an ULI. If you put the time in, I am confident you will see gain. However, this doesn't mean that you should now go and sit and do a 3 hour footlong stretch session, it simply means if you put your time in, you will be rewarded.
You're new, so go steady, and good luck.