As of now, and may be I am wrong, there are very very few trains with 25 coaches (passenger carrying), not goods rakes. But there was a proposal which is being implemented to augment carrying capacity to 25 coaches. Two hitches present themselves. Platforms at major stations are suited for 24 coach rakes only. The sectional length between signals is set for 25 coaches (remember that goods wagos are smaller in length, so please not there will be 30/40 wagon rakes) but these will be within the sectional lengths. Then there is the question of hauling capacity of locos, which are now being augmented on a urgent priority basis, and lack of coaches itself !
I draw your attention in this regard...
more... that after substantial upgradation of the stations and signalling equipment on WR/CR and in MAS(about which I know somewhat), now 9 coach/12 coaches are run on suburban lines, known as MVRC rakes. Same too in MAS suburban section. This is only to supplement the point made in the first paragraph. it does not complement the explanation given above.
Good wishes.
delhimurlidhar@gmail.com