Hi Deepak,
Considering you have core SAP PP skills, should you focus in IBP or explore (Simple)Logistics in S/4 HANA. In fact APO PPDS would have been natural transition for you than DP & SNP modules. Note PPDS is soon moving into S/4 HANA as advanced Production Planning, so focusing on it would be a good idea.
If you are comfortable with APO DP & SNP then you can transition to IBP S&OP fairly quick on the fundamentals although technically there are significant architectural differences. IBP Supply would also make sense and for Demand only the Stat Forecasting part - Demand Sensing is a different beast.
On the other hand IBP Inventory is different from anything in APO SNP unless someone has experience in Advanced Safety Stock Planning or working with SmartOps EIO. IBP Control Tower is interesting - closest I can relate it is Supply Chain Engineer and Plan Monitor in APO that hardly anyone uses. Control Tower fundamentally need understanding of Industry KPIs, SCOR Metrics other than that there is nothing much except managing the data integration from APO (for SNP keyfigures) and ECC (for Sales Orders and Schedule Line / Deliveries).
Longish rant but this is what I have concurred based on my IBP exploration so far 
Cheers,
Somnath