The boy, Ariful Haq Seikh, his grandfather Hasim Uddin Seikh, 55, and grandmother Maforza Khatun, 50, are languishing in Kushtia jail for entering Bangladesh without valid travel documents, said a media report.
Sentenced to two months' imprisonment, their term ended 10 months back, but they have not been freed.
They hail from Murshidabad district in India's West Bengal state.
They entered Bangladesh April 15 last year to visit their relatives in Daulatpur, according to Border Guard Bangladesh (BGB).
They were arrested and sent to Kushtia jail. A month later, a court awarded them two months' jail term.
Then began the process to verify them as Indians.
The jailor wrote to the Inspector General of Police (Prisons) who forwarded it to the ministry of home, from where the letter was sent to the ministry of foreign affairs.
The foreign ministry contacted the Indian authorities and New Delhi responded in positive.
The confirmation process took a year.
On April 15 this year, the home ministry directed the Kushtia jail authorities to take appropriate action.
BGB have now got in touch with India's Border Security Force (BSF) at Nadia in West Bengal and a meeting has been scheduled for April 29.
"We are hopeful that BSF will take the boy and his grandparents back during the meeting," Sultan Ahmed, a BGB official, was quoted as saying.