Approval for charitable registration: prescribed forms, timelines and inquiries determine grant, renewal, or cancellation of tax-exempt status. Approval procedures for trusts and institutions under section 10(23C) set distinct application forms and filing windows: existing entities use Form 10A for five-year registrations with orders due within prescribed monthly timelines; renewals and final registrations use Form 10AB with inquiries and six-month advance filing requirements; new entities receive three-year registrations with one-month advance filing. Conditions for approval require non-commencement or absence of prior exclusion of income under charitable exemptions, permit document calls and inquiries to verify genuineness and compliance, and allow rejection or cancellation after hearing. Investments, deposits back, and loan repayments qualify as application of funds only if made within five years from the end of the previous year in which the corpus or loan application was made.