Assertion: Article 28 prohibits religious instructions in educational institution that are wholly maintained out of State funds except those which are administered by State but are established by endowments or trusts that require religious instruction in such educational institutions.
Reasoning: Sainik Schools and Kendriya Vidyalaya schools can impart religious instructions to students. 

Assertion (A) is true but Reasoning (R) is not correct.

Article 28 prohibits religious instructions in educational institution that are wholly maintained out of State funds. For example, government run schools like Sainik Schools and Kendriya Vidyalaya schools cannot impart religious instructions to students. However, some educational institutions are exempted from this rule, those which are administered by State but are established by endowments or trusts that require religious instruction in such educational institutions. State recognized or State aided educational institutions cannot force any student to take part in any religious instruction or to attend any religious worship conducted in such institutions.