If I completed my 12 in this board than it's valid for BCA and front end developer job profile in future

Hello Student

Board of Open schooling and skill education recognised  by Government of Sikkim by the legislative under act 14 in the year 2020. Association of Indian University has approved this system of education of Sikkim government and its certificates for taking admission in higher education courses. Open schooling of Government of Sikkim has been recognised by NIOS National Institute of Open schooling of India. So all the certificates and degrees available from Board of open school and Skill education of Sikkim Government of Sikkim is valid for any type of admission in India and abroad.

Hope this helps.