Processing time and requirements

I assume your husband is non-EU citizen with approved refugee status in Germany.
In that case you can apply for a family reunion visa at your nearest German embassy. Your application will be forwarded to and processed by the foreigner authority of the German town where your husband lives. Depending on how busy they are, this can take 3 - 6 months.
The requirements are:
- your husband has a legal status in Germany approved for more than a year (very often, refugees get only one year, which means they cannot bring family members)
- your husband has sufficient income (or savings) to pay for the living expenses of both of you (a minimum of €8700/year per person is needed - please note that in reality you will probably need more than this!), although for refugees there seem to be exceptions - some can bring their family even though they depend on government handouts (HartzIV) for their living expenses
- your husband has sufficient living space (e.g. rental apartment) for both of you
- you need to get German health insurance (check whether you can be covered under your husband's health insurance!)
For spouses of German citizens, basic knwoledge of German language is also required - but spouses of foreigners do not need this. (Of course you need German to live in Germany, so you should start learning it in any case!)
Contact the embassy and ask about which documents you should submit and what the process is.

Thank you Beppi for your quick reply
Yes my husband is getting refugee grants from government but what i most want to know is that living space he has is rent one single room can it be possible to live with that space or he want to move bigger living space we do not have children .
And how can we know our process in progress is their any way we can now information of our process or we have to wait period of 3-6 months for the process

Thank u

30-40sqm living space (e.g. a rented one-room apartment) is usually deemed sufficient for a couple, a sublet room of less than 20sqm is certainly not.
During the processing time, it is very difficult to get information about the status. You could try to contact the relevant officer in your husband's city (if you can find out who that is - the embassy will not tell you).