RTO India — slot booking is not allowed

Address:

Transport department of Govt. of NCT of Delhi,Zonal office,West Delhi, Janakpuri, New Delhi, Delhi

Hi my dl number is dl4/0017008/2018 and application number is[protected]. I'm trying to book for a driving test but popup message says application is approved but slot booking is not allowed. My learning dl will expire on 6-june-2019. Please help me to book slot.
I have been trying since 4-5 days first i thought it was a glitch of a website but now i realized i i don't filed a complain i won't be allowed to book.