Unless India can get all of PoK or a benevolent Pakistani government I don't see any other option unless India just loses interest in Central Asia altogether.
Wasn't Iran supposed to be the gateway for India into Central Asian energy markets? Is that sphere just going to be conceded to China?
What about Afghanistan? Without a major trade link to India where do you suppose they will turn to? Preventing Afghanistan from becoming a puppet for Pakistan should be a paramount strategic objective for India and this trade network is a key to that end.
Right now all we have are preliminary reports. Let's be patient for more news to come in. Regarding Afghanistan our options are pretty much limited. Essentially the GoA are on their own. Supplies to Afghanistan from India can & is happening thru the air.
Our disengagement from the rail project doesn't automatically exclude us from exporting goods to Afghanistan thru Iran via the railroads there, irrespective of who builds & operates it. Let's not forget Iran & the Taliban don't get along & will never do so. The best part is none of them are under any illusions as well. Hence whatever relationship does exist between the two is strictly transactional thanks to the US presence there.
That's where India's role is vital as Iran isn't in a financially great position to cater to Afghanistan's needs & China would have it's own agenda. Keeping all this in mind, the Iranians would hedge their bets & not entirely exclude India from Chahbahar.
To conclude, India doesn't have an adversarial relationship with Iran in the way Pakistan does. Our relationship with Iran has been complicated due to global geopolitics , our relationship & dependence on the US owing to our own compulsions thanks to our neighborhood.
Besides, Iran has itself to blame for India's reticence in investing in Iranian projects as in the short time period that the sanctions were lifted, Iran reneged or were threatening to do so from earlier agreements with India on everything from Chahbahar to prospecting from oil & gas in the Persian Gulf to building up of a petrochemical & fertilizer complex in their attempt to strike a hard bargain.
Once Trump reverted with sanctions rejecting the JCPOA, the boot was on the other foot. The
Iranians resorted to pleading, blackmailing, etc . to get us to partner them in those projects .Unfortunately, all this precludes us from playing our legitimate role in the CAR including Afghanistan & in the ME.