Roth IRA contribution for 2019 exceeded per AGI limit. If I file removal of excess form with my financial institute, do they sell off my securities associated with contr?

Yes, the excess contribution will be returned to you. Please see this article about Excess Roth IRA Contributions for how to report this in TurboTax.

I don't know of anything prohibiting a return of contribution from being done in-kind, but I don't think any financial institution would do it.  The amount distributed must include any gain or loss attributable to the contribution being returned and it would be difficult to comply with that requirement unless the distribution is made in cash.