So recently that had done a Private equity placement with the 360 One Funds, @Rs.235/share for 475Cr. (Link)
Since the IPO is a Fresh Issue for Rs.3500Cr, and assuming same valuation of Rs.235, this will be for 14.89Cr shares. But I suspect this might be at a higher valuation. Current equity is 98.88Cr, this will be a ~15% equity dilution. This also pushes Aegis equity stake below 50%.
At Rs.235 IPO Price, Aegis stake will be ~43.54% post IPO, whereas at Rs.350 
IPO Price, Aegis stake will be ~45.5% post IPO. I do not know what the IPO price will be, with market conditions like this.
I suspect till the actual offer opens for bidding (~3-6months), we might get a lot of news/new projects (ammonia, etc) related coming out to higher the IPO price.