score:6
When applying for a visa, you need to figure out the potential red flags. Those are the circumstances which could hurt your case in the eyes of a skeptical immigration officer. To "win", you need to proactively address those circumstances with an explaination. In your case I'd say there are two issues:
You have a brother in Germany, and you're going to Germany. This is a red flag. Why? Because, shall you decide to stay in Germany illegally, this would be much easier for you than if you knew no one there. You can counter this by saying that you've been to Germany before, and always departed in time - and your brother was still there.
You are going for 40 days - which is quite long time for a visit - and you're unemployed. This makes two red flags.
First, there's a suspicion that your main purpose for the trip might involve making some money working under-the-table (since you're unemployed and going for long time). You can counter this by providing an explanation how all your expenses would be covered (and showing the funds to cover them).
Second, being unemployed means there is one less reason for you to depart on time, so if you decide to overstay, it is easier for you. You can counter this by offering other reasons why you'd be back to India in 40 days. For example, there may be an important wedding of your friend you're invited to, there may be a conference you need to attend, you have scheduled several interviews etc.
Explaining those shows to the Consular Officer that you did your homework, and that you know and understand the rules, and understand the importance to play by the rules (since you put effort to explain WHY would you play by the rules).
One more point: be very careful when you state "I have to visit there to help them". If by this you mean you'd be doing what is otherwise considered paid work (for example cooking food, cleaning, babysitting etc), this may be considered working. One of the reasons for that is that if you're doing that, you're taking away a job of a German resident who'd do this instead of you.
However if by "help them" you mean things such as providing emotional support to a family member, this is different, and this would be ok.