Vishista-advaita's meaning of renunciation incoporates the fact that in his or her life one must immerse oneself totally in Creation as the surrender to God the Creator that is Sri Krishna/Devi Durga as two sides of the same coin of God. In the world which is part of the universe Brahma-Nature is therefore a real entity to contend with for the practitioner. The workings of Brahma-Nature must be understood in terms of its complexity from satya-advaita yoga, the yoga of truth-accommodation. This has already been elaborated upon by the author in terms of the guna-consciousness interactions of sattvic, rajasic and tamasic attributes of Brahma-Nature, that are impermanent so leads to challenges to struggle through and navigate ones path through its nuances.
The following link explains the process of how specifically renunciation applies in contending with the process while still remaining immersed in the samsara. - A Bravenet.com Forum