On Q3FY22 con call management provided guideance of distribution of Rs 7-9 per unit in FY23 despite two major contibuting road assets moving out of project. I tried to do some calculation to find out what distribution I can expect from the assets, assuming remaining assets provide same normal NCDF (adjusted for exceptional events).
Find enclosed my wokring for same.

NCDF are in Rs lakhs. Talegaon Amravti, Jaipur Deoli and Omalur-Salem-Namakkal are average for last 5 half years NCDF. Pathankot Amritsar NCDF are for 3 half year ending 1HFY21 (projected was closed due to farmer protest since then and just restarted collection in December 2021) and For Timkur Chitradurg Project I assumed same as for 1HFY22 (as there was very volatile cashflow in previous half yearly NCDF).
IRB InvIT can expect to receive ~ Rs 145 cr as NCDF for 6 months from above 5 projects assuming no traffic growth/normal maintenance and no toll revision. This would mean distribution of ~ Rs 2.5 for 6 months ( Rs 1.25 per quarter) assuming whole NCDF is distributed.
Further for Q4 FY22, I expected around Rs 100 Cr collection from Surat Dahisar and Rs 40 Cr from Bharuch Surat assets, which give further distribution of ~ Rs 2.4 for Quarter.
So in Q4FY22, I expect distribution of Rs 3.66 from IRB InvIT.
Similarly in Q1FY23, only Surat Dahisar would work for April-May 2022 can provide NCDF of around Rs 66 Cr, which can translate in distribution of Rs 1.15 per unit in Q1FY23. In 5 continued assets, we expect distribution of Rs 1.25, so we can expect Rs 2.4 per unit as distribution in Q1FY23.
Then on, in Q2FY23-Q4FY24, assuming again only distribution of Rs 1.25 per unit per quarter, we may expect total distribution of Rs 6.15. This does not assume any traffic growth and toll revision which expected to be in double digit by management due to high WPI.
On current price of Rs 55, I found yield of around 11% which I found attractive in current environment and hence added my holding.
Disclosure: I added around 20% of my current holding in IRB InvIT. My view may be biased due to my holding. I am not recommending any investment in the units. I am not SEBI registered advisor. I have been wrong mutiple times in my projection and IRB InvIT management also have been generally very optimistic in projection as per past 3 year since listing. Investor shall be their own due diligence before taking any investment decision.