SEBI has laid down clear rules for buybacks under the SEBI Regulations, 2018. Key rules include: 

• Maximum buyback size: 25% of paid-up capital and free reserves (for board approval); beyond this, shareholder approval is required.
• The buyback must be completed within 6 months (tender offer) or 1 year (open market). 
• A company cannot make another buyback offer within 1 year of the previous one.
• Minimum 15% of the buyback must be reserved for retail shareholders. 
• The debt-to-equity ratio must not exceed 2:1 after the buyback.