Source : http://www.thehindu.com/society/faith/kinds-of-devotion/article18788328.ece
There are different kinds of devotion to God and we see examples of both Seshatva and Paratantriya in the Ramayana. Seshatva is to not let anything stand in the way of the desire to serve God. Lakshmana wanted to accompany Lord Rama to the forest. Rama tried His best to make Lakshmana stay back in Ayodhya. But Lakshmana refused to be dissuaded by the Lord.
Lakshmana was keen to be with Rama and serve Him at all times. So he was prepared to refuse to obey the Lord’s request. This is an example of Seshatva, said Kidambi Narayanan in a discourse. Nammazhvar too wanted only to serve the Lord and prayed for this.
But Bharata was in a different category. No doubt he too wanted certain things, namely the return of Rama to Ayodhya and the assumption of kingship by Rama. But when Rama said He would not come back to Ayodhya and ordered Bharata to go back to the city and rule as king, Bharata implicitly obeyed his brother. He did not think of himself. He did not insist that Rama go along with what he (Bharata) wanted. This is an example of Paratantriya.
While other Azhvars prayed for being rid of repeated births and for the chance to serve the Lord, Periazhvar only sang for the Lord’s welfare, thereby demonstrating bhakti, which asks for nothing.
Paratantriya is when a person simply obeys the Lord and does not act on his own or for his pleasure.
Suppose a person possesses a doll, decorates it and looks at it thinking how beautiful it looks. Does this act of decorating give any joy to the doll? If a man who has grown saplings in his field transplants them, it is because they are under his control.
So being controlled by another superior being and not acting volitionally is Paratantriya.