After completion of all level's of dis program den what next ?

Question

Eg. u reached end of level 17.

Answer 1

At the end of level 17, there is level 18. The FAQ lists 20 levels:
https://www.sololearn.com/faq
I imagine Sololearn can add more levels later, but there doesn't appear to be any need for it now.
Also, please note that the Q&A section is reserved for coding related questions only. Check out
https://www.sololearn.com/discuss/1316935/?ref=app