The letters asked officials to pay up over Rs 40 lakh or give work to persons assigned by militants.
Militants have called for a boycott of Independence Day celebrations in the Northeastern states.
People are protesting against the killing of 30-year-old Th Manorama Devi, allegedly by Assam Rifles personnel.
The 39-year-old Imphal-based journalist was detained under the NSA on November 26 for allegedly uploading videos criticising the BJP-led governments in Manipur and at the Centre for observing Rani Jhansi's birth anniversary.
A bench of Justice D Y Chandrachud and M R Shah said that his continued detention will be in violation of his fundamental right to life under Article 21 of the Constitution.
Maj Deswal of 21 Para (Special Force) was killed in a gunbattle with Zeliangrong United Front militants in densely forested Nungba area during a combing operation undertaken by Rashtriya Rifles and Special Forces personnel.
A bench of Justice D Y Chandrachud and M R Shah told Solicitor General Tushar Mehta that it was a serious issue as someone lost his liberty since May and the petitioners have prayed for grant of compensation to Erendro for detention.
During a fresh round of talks with North-East Democratic Alliance (NEDA) convenor Himanta Biswa Sarma earlier in the day, the NPP leaders stuck to their demand for change in the leadership of the BJP-led coalition government, they said.
A powerful bomb exploded a few minutes before the celebrations of Independence Day commenced on Thursday in Manipur but no casualty was reported.
A large number of people took out a 'solidarity march' in South Delhi on Sunday in support of Jamia Millia Islamia students and those facing police action during protests against the contentious law.
Clashes erupted between agitators and police in Greater Imphal area on Sunday as supporters of introduction of Inner Line Permit in Manipur continued their defiance of the curfew, which stepped into the fifth day, and took to the streets in large numbers.
A class XI student was killed after school students demanding implementation of Inner Line Permit system in Manipur clashed with police.
The 44-year-old iconic rights activist turned emotional as she licked honey from her palm to end the fast.
Nearly four lakh people have been affected across seven districts of Assam.
The Seismological department said that the quake measured 6.8 on the Richter scale and lasted for about two minutes.
Barring Maharashtra, the poll percentage in rest of the states was in excess of 60 per cent while in Puducherry it was 80.47 per cent.