Main problem with the pipeline for India was terms of payment. India wants to pay only for the gas that it receives at its end, thus insulating itself from the risk in transit countries. TAPI will only work if other countries agree with the idea.
Can you please expand on it?
India was supposed to pay for only its due of gas (~1350mmcfd/ 14bcm/y) plus the transit fee for that portion to Afghanistan and Pakistan (~$0.45/mmbtu to each country), the same fee was to be paid by Pakistan to Afghanistan for its share (~1350mmcfd/ 14bcm/y). India was always paying for it's share of gas. Or were you referring to a common Contract Price (for Afghanistan, Pakistan and India)?
Also, as per shareholders agreement signed in December 2015, both India and Pakistan holds 5% of TAPI Pipeline Company (TPCL) with majority shares (85%) with Türkmengaz. India was only supposed to contribute 5% or $500million against which it (GAIL) should be receiving its share of revenues (5%) generated from sales of 33bcm/y gas to Afghanistan (5bcm/y), Pakistan (14bcm/y) and India (14bcm/y). I am not aware, whether India has renegotiated or proposed amending this shareholders agreement after signage in 2015. If they have, kindly correct myself.