capital gain

Beacuse in debentures and bonds face value are always same for example if u buy a bon of ₹100 in 2015 and redeemed in 2018 u received only ₹100 at time of maturity also because bond face value are not increased by the time, it always remain same. Your main source of income is interest from bonds and debentures. If indentation is allowed in these case you always have capital loss because at time of sale u show ur full value of consideration is 100 and u take index ob 100 rs paid in 2015 so their is always loss that's why department not give indentation on these thing. But their is exceptions u can claim indexation on index bonds only.