As a general rule, when deciding on whether to issue a non-work visa to someone, two things will be considered. One is if you're likely to be problem during the trip, the other is if you're likely to neglect to leave afterwards. To satisfy them on the former, you're often asked to show you have the funds to support yourself, have hotels booked, are of good character etc. For the latter, a return ticket is generally a must, but more may be required depending on your situation.
Based on your rejection, it seems that the Swiss authorities are concerned about the second part. They worry that you will fly out to see your husband on a short stay tourist visa, and then stay. (I've known people have the same rejection reason who work in IT, and are wanting to attend a conference). Sadly, coming from somewhere like India, and having your husband be in Switzerland will make you seem like a high risk candidate.
If you want to appeal the decision / re-apply, you're going to need to show that you have every intention of leaving at the end. (Ideally that should have been in your initial application, it'll be harder now because you didn't include it then). You'll need to find some way to demonstrate you won't just stay with your husband. That could include family back home, a stable job to return to, study courses you're part way through, proof of property owning / long term renting etc. If you can't find enough evidence to convince them that you'll leave, you won't get the visa...
Also, in the comments you asked about timescales. Some countries and some visa classes have targets and guarantees for issuing times (while others it can take a long time). However, generally appeals and second applications are excluded from these, so expect those to take longer, sometimes much longer. Unless your initial application was processed in under 2 days, I'd say it'd be a pretty long shot to get a reconsideration/appeal processed in under 7 days
