Hi Krishna,
sorry for the late reply, i have looked into some of your files, there are lot of small errors that you have made in your designs, probably you are beginning, i gave a link above to start off with. one specific thing that i would like to say is
--> orcad doesn't allow same pin numbers for any component it might allow your component but it will pose lot of problems ahead in your design, now for example if you have 2 Gnd pins on a part then name them as Gnd1 and Gnd2, when the component is complete and you save it, orcad tries to compile the component and if it finds multiple same named pins then it reports you, try to avoid this mistakes as it might not look important for small boards and small components but it becomes crucial for bigger components like FPGAs or any BGAs.
I looked into firealarm1 to firealarm3 i have seen that you have done the design in a hierarchical approach, right now i would say, hierarchical design is a little far-fetched i would suggest you to work on some flat designs first understand them thoroughly and then go for hierarchical designs, you have committed a lot of errors in firealarm3, especially you have not assigned any ports to your hierarchical symbol which is not expected, please try to make some proper flat designs first then you can go for hierarchical design. Hierarchical design is just an aesthetic way of representing your design you can make any hierarchical design as a flat design so don't worry, you need to first master flat designs.
Let me tell you that i was able to successfully generate netlist for firealarm3 and was able to import that in sample board, no errors whatsoever.
Now if i have to suggest you an approach then do the below after you have completed the exercise that i have given the link above, first make a proper schematic, like a xilinx spartan 3A board, below is the link to schematics
https://www.xilinx.com/support/documentation/spar3a-sk.htm
https://www.xilinx.com/support/documentation/boards_and_kits/s3astarter_schematic.pdf
1 -> Download these files and then try to make a schematic which looks exactly similar to the pdf.
2 -> Then manually create all the footprints.
3 -> Do the Layout.
Finally, i'm sorry if i sounded bossy or rude at any point - just trying to help.
Thanks - Hope this helps.