Should I buy 2015 13 inch MBP or 2016 13 inch (non-touch bar) MBP I am planning to buy macbook pro from US this month.(I live in India and one of my friend is coming from US next month). 

Please help me in making right choice-

My options are-

1st choice-  2015 MBP 13 inch with price $1299. I want to do following updates to it:

a. Processor update from i5 to i7. Upgrade cost = $300.

b. RAM upgrade from 8 GB to 16 GB. Upgrade cost = $200.

c. SSD upgrade from 128 GB to 512 GB. Upgrade cost = $400.

Final cost of MBP = $1299+$300+$200+$400=$2199.

pros-

a. performance wise it is similar to 2016 non-touch version.

b. USB and other ports are available.

cons-

a. It is using 5th gen broadwell processor as compared with 2016 skylake processor.

b. Since apple dicontinue product after 5 years, so if I purchase 2015 model now I have 2.5 only years before it is discontinued.
And after that if any part need replacement I will not be able to do that even if it is under apple care after 2.5 years.

2nd choice- 2016 MBP 13 inch non-touch bar version with price $1499. Similar upgrade as above for Processer, RAM and SSD. 
Final cost of MBP = $1499+$300+$200+$200=$2199. After doing upgrades its price is similar to 2015 model with similar upgrades.

pros-
a. It is using skylake CPU.

cons-
a. Ports are removed. I need to buy dongle.
b. There is lot of negative reviews for 2016 model on internet.
3. No magsafe.

3rd choice- I have early 2011 13 inch model. I wanted to upgarde its RAM and SSD and use it instead of buying new MBP. But its battery cycle count is 1060 and since apple has discontiued 
the product I can not get battery replaced with apple manufactured battery and I am not sure about non-apple battery if they will work or not.

My choice is 2015 model but main problem I see in that is it has only 2.5 years before it become discontinued and if I buy applecare after 1 year that will make product warranty 1+2=3 years but MBP time remaining for discontinue is 2.5 years. So 6 months apple care will be of no use.
The crux of your question/decision seems to lie in the following assumption:


  Since Apple discontinue product after 5 years, so if I purchase 2015 model now I have 2.5 only years before it is discontinued. And after that if any part need replacement I will not be able to do that even if it is under apple care after 2.5 years.


However, your assumption is wrong.

I refer you to Apple's policy on Vintage and obsolete products, which outlines their hardware/parts support. 

In summary:


Vintage products are those that have not been manufactured for more than 5 and less than 7 years
Obsolete products are those that were discontinued more than 7 years ago.


Note: Bold emphasis mine.

In essence, the 13-inch MacBook Pro (2015) model is still being manufactured and has not been discontinued yet. Apple's warranty provides global coverage, and if you purchase Apple Care then you will be covered for the whole of that Apple Care period.