How many communication (RJ45, RJ11 and coax) ports I really need in my apartment ?

Their is no answer that is just right for everyone. Different apartments interiors are styled differently based on owner's need and foresight. Infrastructure investment is also a matter of initial pain and latter gain tradeoff which many owners may not be able to appreciate. Here is what I think, i am going to plan my potential port allocation at different places may be like:

Any TV Area (1 ft height) - 6 ports:

1. IPTV STB – 1 RJ45 Nos.
2. Internet and LAN television (n STBs but only one used at a time, n indeterminate (1-10 possibly)) – 1 RJ45 Nos.
3. Cable Television – 3 RG6 COAX Nos. (1 for cable TV/Terrestrial radio and 2 for DTH)
4. Smart TV Unit – 1 RJ45 Nos. ( They use this to upgrade the firmware (and use some smart features).

Any Study Table/Area/Desk (4 ft height) - 5 ports :

1. Data – 2 RJ45 (study table (not in LR)
2. Telephone points – 2 RJ11 (1 for Landline, 1 for intercom)
3. VoIP Phone - 1 RJ45 POE Nos.
4. No TV

False Ceiling in BRs, LRs, FRs and DRs - 2 ports:

1. Wifi Access Point – 1 RJ45 PoE Nos.
2. CCTV camera – 1 Nos. (only provision, not use for privacy or use in maid visiting hours only)
3. No telephone or TV

That's a lot of ports in house and almost 100% owners would not have initially planned like this.  Its perfectly fine that you can assume i have started doing drugs, have lost my mind and restrict yourself to only data point per room (and distribute using small switch if required). Fact is new data point use cases emerge over time.  and individual flat resident needs are different: some people will like to go for one AP per room, while others may go for one AP for whole flat. Some may go for CCTV only in 2 points, others at more and most probably none.

Apart from my above hyperbole list, there may be other locations that need only CCTV, Only Wifi AP, Only landline, intercom and VoIP phones, etc. It can only be done with your interior work and some amount of conduit and cabling rework  is unavoidable.  We can only recommend that one be generous with conduit laying and face-plate allocation (even if no wires are drawn or ports installed) so that extension is easier down the line (no need to chip walls or expose ugly casings on the surface). Conduit design (where to use thick, where to use medium, where to use thin) plus where all to provide conduits is the most important consideration.

Cabling design - type, number can always be changed later. For eg., Its possible to use a star point in every room for RJ45 and connect it to main RJ45 STAR hub point for the flat rather than use every cable as a home run to central star point. Not every device needs 1 GbE. For eg., TVs doing 1080p, VoIP Phone, CCTV streaming needs less than 10 Mbps today. In future TVs maybe they will need 100-200 Mbps max (next 10 years).  Every such STAR point will have to have a small network switch (8 port). Similarly some cat6 can be replaced by Fiber optic cable if required 20 years down the line.

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