Where all are IP typically cameras mounted and any difficulties arise in mounting them ?

IP Cameras may need to be mounted on surfaces such as walls, ceilings, false ceilings, metallic partitions (eg. lift) or Poles. This involves some complexities challenges such as:

(1) At times poles are imaginary during design and must be first installed before camera is mounted. The  installation of pole itself may be on ground, and on railings

(2) At times camera may need to be mounted on ceiling but at a height lesser than ceiling (or at a virtual ceiling that exist in air). 

(3) their maybe no space or flat surface to drill screws, but only a small frame etc.

While many CCTV pole designs, mounting stand systems, etc. for CCTV cameras are available in market, it may not suit the requirement or gel well with the landscaping or interiors or even be robust enough for the deployment case. To get the installation move forward, therefore you may need to adapt the mounts (not just the camera regular mounting system) or get a custom mounting system fabricated to meet your demands of aesthetics, robustness, cable concealing, etc. We have no guidelines or template for this , except the advice that you should be ready to design one in case the readymade products do not meet your expectations, and get it fabricated using any local metal/aluminum fabricator, even if you have to pay premium for custom job and low quantity (you are not anyways going to get this problem in scale of 1000s for you to really make price similar to what's available in market.

Our project got special mounting system done for few elevator cameras, railing mounted poles (non-welded type but bolted with Nut Bolts) on podium, basement cameras to lower camera height below surrounding pipes, etc. In most cases, system integrators should do this, but at times their interest  (want to reuse left over stock from other project or USE what they have for similar use case) may clash with your expectations, requiring special design effort from you. Don't worry, its easy. And your will take pride in the work when its finished. 

- Suman Kumar Luthra @ APRC-P3 Telecom Sub-Committee