The 80-year old writer has not been keeping well since the last few months, they said.
Known for his work 'Sila Nerangalil Sila Manidhargal' among others, Jayakanthan was awarded the Sahitya Akademi Award in 1972.
Called as 'JK' among novelists and literary enthusiasts, Jayakanthan was awarded Jnanpith Award in 2002.
In 2009, he received 'Padma Bhushan'.
In honour of his translation works of Russian novelist Pushkin, the Russian government also awarded him the 'Order of Friendship' in 2011.