@ashwinidamani suggest you to go through this thread, the HBL stock story thread posted by @valuequest07 , HBL presentation on the exchanges and Kernex AGM recording (not sure where it is) to get to understand the HBL story in detail.
On the TCAS side: As per multiple government sources (public) the TCAS opportunity is for 35000 Km to 60000 Km. Last year around 3000 Km was tendered at roughly 60 lac/KM. The budget target this year is for 5000 Km which should be around 3000 cr. for all three players. The government intends to complete 35000 Km in next 5 years, there is also a possibility of more players coming in. As per Kernex AGM the EBITDA margins are over 25% and with very little dep. would mean around 15% PAT margins. There is also an O&M component for 15 years 2/3 years post installation at 5% of the tender value. Assuming HBL at the end of 5 years does around 10000 Km, the O&M itself would be at 300 cr annual run rate and assuming they do a good job at TCAS most of it should flow to PBT.
HBL is not a one race pony there are so many large high margin opportunities like Artillery fuzes, TMS, Electro Optics, Grenades, PLT batteries etc. There are also risks since a lot of these are B2G opportunities but what TCAS does is it gives at least a 2 year time period for these opportunities to come to fruition.
Highly recommend going through the stock story by @valuequest07 .