Read the DGCA rules a little bit more carefully
The requirements for renewal of license are
Within the last 6 months
1. 10 hours PIC
or
2. Skill test by day and night ( IR as well if you wish to renew IR )
I am not sure about the 10 hours PIC but the skill test has to be done on an aircraft already endorsed on the license
In your case since you only have the piper twin commanche you wont be able to do a skill test (or renew the multi IR ) since the DGCA no longer recognises it.
My suggestion would be to add a single engine rating to your license after passing the tech specific and flying the single for 6 hours
If you do this 6 months prior to expiry of license you can count the skill tests automatically towards the renewal of the license
If you already have a single engine on your DGCA license then doing the skill test by day and night are more than enough to renew it
As far as RT is concerned as long as you have a valid RTR P license it dosent matter whether or not you have an RTR A License ( after passing part 1 and part 2 )
That being said if you get an RTR A license you can apply for lifetime validity which you cant obtain by converting a foreign RT
Your RT license should be valid prior to any flying and for renewal of CPL
Another issue is the DGCA now wants an ELP endorsed on the CPL . You need to get it endorsed prior to any flying because you cant exercise the privileges of the CPL unless you have an ELP endorsed
Application for renewal of CPL to be done at your nearest DGCA regional office
This application form should help clear some of your doubts
http://www.dgca.nic.in/circular/FCL1_2010R1.pdf