According to Garurd Puran, Pitra Paksha falls on Ashwin Maas, Krishn Paksha, 15 Days allocated to Pitra's

CAN DO's

1. You can continue to do your regular Pujas.

2. You can Light diya at your puja place as normal

3. You can continue to do your regular Vrats like ekadashi, monthly Shivratri etc

4. Can do Normal Daan to Brahmins or Poor (without Sanklap) "nishkaam way"

5. Can do your Pitra Puja's if you doing it annually

6. If you have Surya Dosha in your Kundali - You can Do Pitra Daan or Pitra Puja

7. You can do Nishkaam Dev Puja - without sanklap

8. You can offer Daily water offering to Sun , saying "Om Pitra devaye namah"

9. 8. You can offer Rice in front of Lord Shiva or Vishnu , saying "Om Pitra devaye namah" during your normal Puja.

10. Can do Pitra Daan to Brahmins

11. Can continue with your normal Meditation etc

.

CAN'T DO

1. Cannot do any of your annual Puja's

2. Cannot buy new car or House

3. Cannot start a new venture

4. Cannot do any puja with Sanklap (desired Puja)