The group said they would go to Prime Minister Prayut Chan-o-cha's house from Phahonyothin Road, turn right at Soi Phahonyothin 2 and turn left at Vibhavadi Rangsit Road.
They added that police would allow them to go to the prime minister's house if they used this route as they had negotiated with a senior police officer.
Earlier, Thalu Fah Facebook page accepted donations, saying they lacked protective equipment.
"Therefore, we are now accepting donations for purchasing protective equipment and supporting the demonstration," the page said.
Thai police clashed with protesters on Sunday, using water cannon and teargas against demonstrators who reportedly hurled projectiles towards them.
Police launched a crackdown at Sam Liam Din Daeng junction on Sunday evening, the press reported.
At 7.15pm, protesters burned a police fort in the area, the same one that was burned during the rally on August 10.