Yes you can definitely participate in second round of uptu counselling directly if you have not applied in first round as according to the eligibility criterion of 2nd round following students can apply directly

Fresh candidates who are not registered in the earlier round can register and pay the registration fee to participate in this round.

Those who are registered earlier but have not paid registration fee, need to pay registration fee to participate in this round.

Those who have registered and also paid registration fee but have not submitted any choices in the earlier round.