Visarjan is a Sanskrit word that refers to final ritual and act of respectfully requesting to departure of the deity.
At the beginning of any Puja, the presiding deity is first invoked in a Murti (idol) for the purpose of worship. At the end of the Puja, the presiding deity is requested to depart from the Murti.
After performing the Puja as mentioned above, all the children, men and women present during the Puja should hold flowers in their hands and chant the praises of Lord Ganesha, Maha Lakshmi, Maha Kali, Maha Saraswati and Kubera and bow down to them while offering flowers to them in the order of the young to old.
After offering obeisance, the worshiper should take Akshata (Unbroken Rice) and flower in his right hand and chant the following Mantra for Visarjan -
यान्तु देवगणाः सर्वे पूजामादाय मामकीम्।
इष्ट-काम-समृद्घ्यर्थं पुनरागमनाय च॥
Yantu Deva-Ganah Sarve Pujamadaya Mamakim।
Ishta-Kama-Samriddhyartham Punaragamanaya Cha॥
मन्त्र अर्थ - सभी देवगण मेरे द्वारा की गयी पूजा को स्वीकार कर अभीष्ट कामनाओं की समृद्धि के लिये पुनः आगमन हेतु यहाँ से विदा हों।
Mantra Translation - All the deities should accept the worship done by me and leave from here to come again for the fulfillment of desired wishes.
After chanting the above Mantra, the person performing the puja should bow down to the deities by leaving Akshata and flowers in front of Them. All the people participating in the Puja should bow down to the Pandit Ji, give Dakshina and take the Prasad.