6500 gross is that enough?
Well, we would need to know where you are from (citizenship and residency), how old you are, what your qualifications and experience are, whether your husband will be working, too, and generally why you want to come to Poland, and to Katowice in particular.
Generally, if your husband does not find a job BEFORE he comes to Poland, it will be difficult to find one once he arrives. So unless your husband is proficient in some exotic, in-demand IT skills, don't count on him finding a decent paying job. Generally, wages he will receive for a job that he finds once he is in Poland will be significantly less attractive than for a job that he finds ahead of time in your home country before he arrives in Poland.
Also generally, 6500 gross is OK for a single male at the start of their career, not attractive for a couple, and out of the question if there are children involved. Cost of living is significantly higher for females, who generally do not want to continue a student-like existence after they enter the work force. Single males simply deal with privation and fiscal discipline a lot better than females.
Katowice is (rightly) considered one of the ugliest cities in Poland, if not the ugliest. On the upside, the cost of living is a bit lower than in the attractive cities like Wrocław and Kraków.
If your husband will not be working, he is going to hate Katowice unless he is able to keep himself occupied. That is going to cost.
Really, 6500 gross for a couple is not attractive for a foreign couple unless they are fresh out of school. That is only 21,000 USD per year, which is below the minimum wage for burger flippers in some places in the US. You are not going to be able to save more than a token amount on that pay: a couple of thousand USD at the most, if anything at all. Hardly worth relocating to Poland for, even if you are fresh out of school. Forget about building up a nest egg for your future home and family.
Explore better paying opportunities in the richer countries of Western Europe or the English-speaking countries, where you will be able to SAVE as much as you EARN in Poland, or more.