As soon as the Federal Office for Migration and Refugees (BAMF) makes a positive decision in your case, you will be required to find your own apartment and arrange to rent it yourself. You can find information on searching for suitable accommodation here (Information sheet about 'Housing').
Before concluding a rental agreement, you should find out all the information you need to know: how much you will have to pay in rent and any ancillary costs (especially heating costs), the charge for the security deposit, the length of the lease (temporary or unlimited), and any renovation commitments.
Read this guide for information about what you need to know when renting an apartment in Germany.
If you are unable to meet your living expenses yourself, the Job Centre will bear the costs for your apartment. You should submit an application in good time and take advantage of the assistance offered by an advisory service. When looking for accommodation, you must take into account the guidelines provided by the Job Centre in terms of the size of the apartment and the level of rent charged. When you view the apartment, ask for a detailed rental offer made out in your name, with a breakdown of the rental charges. You should then submit the rental offer and an application for approval to the Job Centre so that a decision can be made. If you wish the Job Centre to bear the rental and removal costs, it must approve your application before you sign the rental agreement. Once you have signed the rental agreement, you can apply to the Job Centre for payment of the security deposit and removal costs, and for basic items of furniture.