Answer

Yes, in general you can do Bhagwan puja if someone who is not related to you has died in your building.

Explanation

In Jain Dharma, the main focus is on bhav-shuddhi — purity of intention, mind, and devotion.

• A death in another home or flat in the same building does not usually stop your personal puja.
• If the death is not in your own family, there is generally no Jain restriction on doing Bhagwan puja.
• If your own family or local Jain community follows a specific custom, you may respectfully follow that tradition.

Spiritual Understanding

Jain puja is done with:

• reverence,
• inner purity,
• and devotion.

A nearby death does not pollute your devotion. What matters most is that you keep your mind शांत, respectful, and focused on the Bhagwan.

Takeaway

You may do Bhagwan puja. If the death is not related to you, it is generally acceptable in Jain practice. If you want, I can also tell you the usual Jain rule when the death is in your own family.