For CDS II 2018 Registration already closed and You must be below 24 years to apply for all the three arms. If someone holds commercial pilot Licence by DGCA then relaxation is given. This year in CDS2 they demanded candidate must born after 2 July 1995. But you missed this chance and next year that is CDS1 2019 there would be a six-month increase in Maximum age so in that also You will be overaged.

You can apply for CDS OTA in 2019 CDSI. That will be probably your last chance to go for CDS.

For detailed information You can see official notification by UPCS at the following link:

http://www.upsc.gov.in/sites/default/files/Notice-CDS-II-2018-Engl_0.pdf