This is a composite character. In the centre, the verb to encounter is followed by the noun chukar. Then, those two characters are surrounded by the glyphs which mark the beginning and the end of an area. It is an ideograph for a ring in which a bird fight takes place, in other words a cockpit.
Illustrative Text References:
Mohenjo-daro: Tablet in bas-relief: M-446 A: Jagat Pati Joshi and Asko Parpola, 1987: Corpus of Indus Seals and Inscriptions: Volume 1: Page 110: Collections in India: Suomalainen Tiedeakatemia.
Mohenjo-daro: Tablet in bas-relief: M-2017 A: Asko Parpola, B. M. Pande, and Petteri Koskikallio, 2010: Corpus of Indus Seals and Inscriptions: Volume 3,1: Page 102: New material, untraced objects, and collections outside India and Pakistan: Suomalainen Tiedeakatemia.
Comment:
There are a number of tablets, where the same lone sign appears on one or both sides of the tablet. The tablets may have been tokens which permitted access to a bird fight.
Image Credit:
Indus Script Sign Number 63: Sign List of the Indus Script: Iravatham Mahadevan, 1977: The Indus Script: Texts, Concordance and Tables: The Director General Archaeological Survey of India.