After those two years can I renewal the permit or what can happen?

Once approved you will have a 2 year period of DACA approval. Under the current state of affairs, prior to the expiration of the 2-year period you can apply to renew DACA. Remember that Congress is currently considering Comprehensive Immigration Reform (CIR). Check with competent counsel in the event there is a change in the law , because the procedures may change depending on what the new law says. Keep up to date with this.