WELL i didnt knew any thing about it , so just googled
Surya Namaskara (pronounced SOOR-yah nah-mahs-KAHrah,[2] /su:rjə nəməska:rə/) (Sanskrit: सूर्य नमस्कार; IAST: Sūrya namaskāra), known in English as Sun Salutation (lit. "salute to the sun"), is a common sequence of Hatha yoga asanas. Its origins lie in a worship of Surya, the Hindu solar deity. This sequence of movements and poses can be practised on varying levels of awareness, ranging from that of physical exercise in various styles, to a complete sadhana which incorporates asana, pranayama, mantra and chakra meditation.
This is a religious practice , so Muslims should specifically boycott this activity if its being enforced without their will.
Lie of Indian secularism is exposed so many times and its clear like daylight. IMO in secular country no religious practices should be enforced.