How to split a list into two columns?

I think my logic is right, but this way it does not divide it is just one underneath the other and I want two

                {this.state.paises.map((country,index)=>{                  

                   return(  

                        <div>                                                          

                            <div className="row">
                                {i==tam? 

                                <div className="col-sm-6 ds">    
                                <li key={index}>{country.toponymName}</li>
                                </div>
                                :
                                <div className="col-sm-6 ds">      
                                <li key={index}>{country.toponymName}</li>                                    
                                </div> 
                                }                                                                                       
                             </div>

                        </div>

                    );
                    i++;
                    })}