Board examinations for home schooled students

Which board examinations (for both 10th and 12th), a student can take as a full-time home schooler? how to do lab activities? is there an alternative/hybrid model?

The National Institute of Open Schooling (NIOS) is an autonomous Institution under Ministry of Education, Govt. of India, is an 'Open School' to cater to the needs of a heterogeneous group of learners up to pre-degree level (senior secondary/12th). https://www.myschoolz.com/blog/what-is-nios-national-institute-of-open-schooling

- CISCE (ICSE & ISC) does not allow private candidates. - CBSE accepts private students, but with certain criteria. Regular discretionary homeschooling does not meet that criteria. - Cambridge Assessment (IGCSE & A/AS Level) allow private candidates through affiliated schools (only if school accept private students). - IB board does not grant diploma, but students can take individual courses for learning.